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Table of Contents and Key Words/Issues
COMPLETED NOX ACTIONS RELATED TO OZONE POLICY
1. Nitrogen Oxides Supplement to the General Preamble (57 FR
55620, 11-25-92)
Key words/issues; NOx issues not discussed in the April 16, 1992
General Preamble; including NOx RACT, new source review,
interaction of Title I and IV, ozone transport regions, section
185 B report and section 182(f). (page 1)
2. Questions & Answers on Nitrogen Oxides Emissions Policy (2-2-
93 T. Helms memo to Air Branch Chiefs, Regions I-X)
Key words/issues; Modeling; Deadline for implementing NOx RACT
rules; NOx RACT Committal SIPs. (page 14)
3- Fuel Switching to Meet the Reasonably Available Control
Technology Requirements for Nitrogen Oxides (July 30, 1993 M.
Shapiro memo to EPA Regional Office Division Directors)
Key words/issues: Electric power utilities; switch to natural
gas; in the summertime. (page 19)
4. SIP Requirements for Areas Submitting Requests for
Redesignation to Attainment of Ozone and CO NAAOS on or after
November 15, 1992 (9-17-93 M. Shapiro memo to EPA Regional
Office Division Directors)
Key words/issues: NOx RACT exemption request; areas
redesignating to attainment. (page 33)
5. NOx Substitution Guidance (December, 1993)
Key words/issues; Substitution of NOx reductions for VOC
reductions; post 1996 reasonable further progress. (page 43)
6. Guideline for Determining the Applicability of NOx
Requirements Under Section 182m (December 16, 1993)
Key words/issues: Exemption from NOx requirements; criteria.
(page 54)
7. Nitrogen Oxides fNOx) Reasonably Available Control Technology
for the Reoowerina of Utility boilers (3-9-94 J. Seitz memo to
EPA Regional Office Division Directors)
Key words/issues: Replacement of existing boilers. (page 86)
8. Cost-Effective Nitrogen Oxides fNOx^ Reasonably Available
Control Technology (3-16-94 K. Berry memo to EPA Regional Office
Division Directors)
Key words/issues: NOx RACT; Cost effectiveness; cost, and
emission reductions. (page 91)
9- Nitrogen Oxides Questions from the Ohio EPA (3-30-94 T. Helms
memo to the Air Enforcement Branch, Region V)
Key words/issues: Seasonal NOx RACT rules; 3,0 day rolling
average; NOx emission trading; Fuel switching; NOx compliance
schedules. (page 96)
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10. Section 182 ff) NOx Exemptions—Revised Process and Criteria
(5-27-94 J. Seitz memo to EPA Regional Office Division Directors)
Key words/issues: NOx RACT exemptions; process; clean data areas.
(page 100)
11. Conformity: General Preamble for Exemption from Nitrogen
Oxides Provisions: (6-17-94 59 FR 31238; Office of Mobile
Sources General Preamble)
Key words/issues: Conformity; NOx. (page 110)
12. RACT and Innovative Control Technology Projects (7-5-94 J.
Seitz memo to EPA Regional Office Division Directors)
Key words/issues: Extension of the NOx RACT compliance date;
innovative controls; environmental benefits. (page 115)
13. Clarification of Policy for NOx Substitution (8-5-94 J.
Seitz memo to EPA Regional Office Division Directors)
Key words/issues: NOx substitution; attainment plans. (page 119)
14. De Minimis Values for NOx RACT (1-1-95 T. Helms memo to Air
Branch Chief, Region I - X)
Key words/issues: Gas turbine; Internal combustion engines;
Process heaters; boilers; de minimis; NOx RACT. (page 123)
15. Scope of NOx Exemptions (1-12-95 T. Helms memo to Air Branch
Chiefs, Region I - X)
Key words/issues: Effect of EPA granting a NOx exemption.
(page 151)
16. Section 182ff) NOx Exemptions—Revised Process and Criteria
(2-8-95 J. Seitz memo to EPA Regional Office Division Directors)
Key words/issues; NOx exemptions; interstate transport; section
110(a)(2)(D). (page 154)
17. September 12. 1995 letter from J. Seitz to the Mid-Atlantic
Regional Air Management Association . the Northeast States for
Coordinated Air Use Management, and the Ozone Transport
Commission
Key words/issues; New source review; attainment demonstrations;
Reasonable further progress; geographic considerations.(page 157)
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INTRODUCTION
Title I of the Clean Air Act Amendments of 1990 contains many
new and revised requirements for areas that have not attained the
air quality standards for criteria pollutants including ozone and
nitrogen dioxide. The EPA developed a guidance document, called
the General Preamble to Title I to assist States regarding the
interpretation of the various provisions of Title I. The general
preamble was published on April 16, 1992.
On November 25, 1992, EPA proposed additions to the original
General Preamble where it did not cover certain provisions
regarding nitrogen dioxide (the control of which is referred to as
nitrogen oxides(NOx)). This document includes a copy of the
November preamble and several other guidelines and policy
memorandum which EPA wrote to explain NOx policy in the Act. The
guidelines and memorandums can be grouped as follows:
-Questions and answers that cover such issues as dispersion
modeling, deadlines for implementing NOx RACT rules, and NOx RACT
Committal SIPs, (RACT means Reasonably Available Control
Technology)
-Fuel Switching to meet the RACT requirements for Nitrogen Oxides
-Relationship of NOx RACT requirements to requests for
redesignation to attainment for ozone and carbon monoxide
-NOx Substitution Guidance
-Requests for NOx RACT exemptions under Section 182(f) of the Act
-NOx RACT for repowering of utility boilers
-Cost-effective estimates for NOx RACT
-Failure to submit NOx RACT rules
-Deminimis Values for NOx RACT Rules
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Document 1 (D-l)
State Implementation Plan; Nitrogen Oxides Supplement
to the General Preamble for the Implementation of Title I of
the Clean Air Act Amendments of 1990
(11-25-92, 57 FR 55620)
This action supplements the original General Preamble (April
16, 1992) by adding provisions concerning emissions of nitrogen
oxides (NOx). Specifically, the General Preamble did not include
a discussion of the new NOx provisions with respect to the
following topics: RACT, NSR, interaction of titles I and IV,
ozone transport regions, section 185B report, and Section 182(f).
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55620 Federal Register / Vol. 57, No. 228 / Wednesday, November 25, 1992 / Proposed Rules
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 52
IFRL-4530-5]
State Implementation Plans; Nitrogen
Oxides Supplement to the General
Preamble for the Implementation of
Title I of the Clean Air Act
Amendments of 1990
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Supplement to the general
preamble for future proposed
rulemakings. -
SUMMARY: The General Preamble for
implementation of title I of the Clean Air
Acl (CAA) Amendments which was
published on Apnl 18,1992 (57 FR
13498), does not address several new
provisions of the amended CAA
concerning emissions of nitrogen oxides
(NO,). Specifically, the April 15,1992
General Preamble does not include a
discussion of the new NO, provisions
with respect to the following topics:
reasonably available control technology
(RACT), new source review (NSR),
interaction of Title I and IV, ozone
transport regions, section 185B report,
and section 182(f). The purpose of this
NO, supplement to the General
Preamble is to provide guidance on
implementation of these NO, provisions.
As State plan subrnittals are received,
EPA wil! publish Federal Register
proposals inviting comment or. whether
the submittals should be approved. Each
proposal inviting comment will state the
address and closing date for submittal
of comments to the appropriate EPA
Regional Office.
FOR FURTHER INFORMATION CONTACT:
Mr. Dei.? Grano, Strategies and Policy
Section, bzone/'CO Programs Branch,
MD-15, at (919) 541-3292, U.S. EPA
Research Triangle Park, NC 27711.
SUPPLEMENTARY INFORMATION:
Note: In accordance with 1 CFR 5.9(c),
this document is published in the Proposed
Rules category
OUTLINE
1 Introduction
1.1 General Preamble to Title I
1.2 Supplement to the General Preamble to
Title I
1.3 New NOn Requirements
1.4 NOX for VOC Substitution
1.5 Section 185B Report
1 6 Section 182(f) Demonstration
1.7 Attainment of the Ozone NAAQS
2 Applicability and Due Dates for NSR and
RACT Rules
2.1 Marginal Ozone Nonallainmen! Areas
2.2 Moderate, Serious, Severe and Extreme
Ozone Nonattainment Areas
2.3 Ozone Transport Region
24 Major Stationary Source
24.1 Ozone Nonattainment Areas
2 4.2 Ozone Transport Region
2 5 General Due Dates for NSR and RACT
Rules
2.5.1 NSR
2.5.2 RACT
2.5.3 Ozone Transport Region
2.6 Alternative Schedules for NO» RACT
Rules
2.6.1 Section 110(k) Conditional Approval
2.6.2 Phase-in of Controls Beyond May
1995
2.7 Section 182(f) Demonstration
3 New Source Review
3.1 General NSR Requirements
3.2 NSR in Submarginal Areas
3.3 NSR in Marginal Areas
3.4 VOC and NOX Emissions
3.5 Prevention of Significant Deterioration
(PSD)
3.6 NSR Offset Commitment
4 Reasonably Available Control Technology
4 1 Background
4.2 General Definition of RACT
4.3 Relation to ACTs
4.4 Relation to Title IV
4.5 Relation to VOC RACT Policies
4.6 RACT for Certain Electric Utility Boilers
4.7 RACT for Other Utility Boilers and
Source Categories
4.8 Enforceability
5 Emissions Trading and Economic
Incentive Programs
5.1 Emission Trading Policy Statement
5.2 Economic Incentive Programs
5.3 Geographic Limitations
5.4 Relation to Title IV Required
Reductions
6 Section 182(f) Applicability Guidance
6.1 Background
6.2 Administrative Procedures
6.3 Ozone Transport Region Attainment/
Unclassified Areas
6 4 Relation to the SIP
7 Control Technology Information
7.1 Alternative Control Technique (ACT)
Documents
7 2 Section 185B Report
7.3 Section 108(h) Clearinghouse
8 NO. Reductions Needed to Attain the
Ozone NAAQS
8.1 Attainment Demonstration
8.2 Advanced Control Technologies
8.3 Transported Pollutants
9 Other NO, Related Provisions in Title I
9.1 Contingency Measures
9.2 Rule Effectiveness
10 Other Requirements
10.1 Executive Order 12291
10.2 Regulatory Flexibility Act
1. Introduction
1.1 General Preamble to Title I
Title I of the CAA Amendments of
1990 contains many new and revised
requirements for areas that have not
attained the national ambient air quality
standards (NAAQS) for ozone, carbon
monoxide (CO), paniculate matter (PM-
10), sulfur dioxide (SO?), nitrogen
dioxide (NOa), and lead. The EPA
developed a guidance document, called
the General Preamble to title I. to assist
States regarding the interpretation of the
various provisions of title I. as amended.
The General Preamble was published
April 16,1992 (57 FR 13498).
The General Preamble principally
describes EPA's preliminary views on
how EPA should interpret various
provisions of title 1, primarily those
concerning State implementation plan
(SIP) revisions required for
nonattainment areas. Although the
General Preamble includes various
statements that States must take certain
actions, these statements are guidance
made pursuant to EPA's preliminary
interpretations, and thus do not bind the
States and the public as a matter of law.
In the near future, EPA will (i) begin to
take action, pursuant to notice-and-
comment rulemaking, on SIP revisions
submitted by the States, and (ii) issue
rules, pursuant to notice-and-comment
rulemaking, on various title I provisions.
During the comment periods for these
subsequent actions, members of the
public will have the opportunity to
comment on the relevant issues.
The EPA's interpretation of the title I
provisions will provide a basis for
subsequent approval or disapproval of
SIP submittals concerning NAAQS
nonattainment areas. While this
Preamble contains guidance on the
interpretation of the majority of the title
I SIP requirements, unique
circumstances or as yet unrecognized
issues are likely to cause case-by-case
exceptions to arise. The EPA intends to
provide the public with a formal
opportunity to comment on the
provisions of this Preamble and other
issues that may arise during subsequent
rulemakings that take action on SIP
revisions submitted by the States under
title I and that set out EPA policy on
various aspects of title I.
The General Preamble focuses
primarily on the SIP submissions
required for nonattainment areas under
part D of the amended CAA. 11 discusses
specific issues concerning the proper -
interpretation of the title I requirements
for areas designated nonattainment '
(and, for some pollutants, classified) ;
under part D, title I, as well as the
proper treatment of nonattainment are**'
that fall outside of the classification
schemes. The General Preamble
discusses requirements for the SIP J
submissions required for ozone, CO, }
PM-10, SOz. NOi, and lead
nonattainment areas. In addition, the
Preamble discusses interpretation issaet
that have arisen concerning 1
redesignations to attainment, some -7
general SIP requirements, and EPA ',
action on SIP submissions, as nreil as •
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Federal Register / Vol. 57. No. 228 / Wednesday. November 25. 1992 / Proposed Rules
55621
(he vnrious types of possible Stale
failures to meet certain requirements
and the consequent sanctions and
Federal implementation plans (FlPs).
The General Preamble also sets forth
EPA's interpretation of the various
provisions in the amended'Act which
change NSR requirements for new and
modified sources in nonattainment
areas. The discussion includes EPA's
intended interpretation of the miramum
changes all States must make in their
SIPs in order to comply with the
amended NSR requirements and the
deadlines for making these changes.
The EPA encourages States to refer to
the General Preamble as their SIPs are
revised to meet the CAA requirements.
1.2 Supplement to the General
Preamble to Title I
The General Preamble published on
April 16,1992 does not address several
new provisions of the amended CAA
concerning emissions of oxides of
nitrogen (NOX)- Specifically, the General
Preamble does not include a discussion
of the new NO» provisions with respect
to the following topics: RACT, NSR,
interaction of titles I and IV. ozone
transport regions, section 185B report
and section 182(f). The purpose of this
supplement to the General Preamble to
title I is to provide guidance on
implementation of these NOX provisions.
1.3 New AfOx Requirements
Section 182(f) requires States to apply
the same requirements to major
stationary sources of NOX as are applied
to major stationary sources of volatile
organic compounds (VOC). As
described in sections 3 and 4 of this
document, the new NOX requirements
are RACT and NSR for major stationary-
sources in certain ozone nonattainment
areas and throughout any ozone
transport region.
The RACT requirements are in section
182(b}{2). The NSR requirements are in
section 182(a)(2)(C) and in other
provisions in section 182. The RACT and
NSR requirements for major sources in
attainment/unclassified portions of
ozone transport regions originate in
section 184(b)(2).
1.4 ;VOx for VOC Substitution
Under section 182(c)(2)(C), NO,
Control, the Administrator must issue
guidance concerning the conditions
under which NOX control may be
substituted for the VOC control required
to meet the post-1996 VOC emissions
reductions progress requirements or
may be combined with VOC control in
order to maximize the reduction in
ozone air pollution for purposes of
meeting those requirements. In order to
substitute NOX reductions for VOC, the
State must demonstrate to EPA,
consistent with the EPA guidance, that
the NOX reductions would result in
reductions in ambient ozone
concentrations at least equivalent to
that which would result from the amount
of VOC emission reductions otherwise
required.
In accordance with guidance to be
issued by EPA. a State may demonstrate
to the Administrator that the NOX
substitution is justified. The EPA will
make a formal determination on any
State request when the Administrator
approves a plan or plan revision. The
EPA's decision will be based on the
documentation provided by the State
and application of the EPA guidance.
The EPA encourages the States to
consult with the appropriate EPA
Regional Office during the development
of the demonstration and plan revision
to ensure that any such substitution is
approvable and that any required rules
can be adopted in a timely manner. If
NOX reductions are to be substituted for
the required post-1996 VOC reductions.
the NOx emissions must meet the
guidance required under section
182(c)(2](C) and must meet the same
creditability constraints dictated by
sections 182(b)(l) (C) and (0) as apply to
VOC emission reductions.
1.5 Section 185B Report
Under section 185B, the
Administrator, in conjunction with the
Nation Academy of Sciences, is to
conduct a study on the role of ozone
precursors in tropospheric ozone
formation. The study must examine the
role of NOX and VOC emission
reductions, the extent to which NOX
reductions may contribute (or be
counterproductive] to achieving
attainment in different nonattainment
areas, the sensitivity of ozone to the
control of NOX. the availability and
extent of controls for NOX, the role of
biogenic VOC emissions, and the basic
information required for air quality
models.
A draft version of the section 185B
report is to be made available for a 30-
day public comment period, and a final
report submitted to Congress. The EPA
is to use all available information as
well as develop additional information
in conducting the study. The National
Research Council announced the
completion of the NAS portion of this
report on December 13,1991. The
section 185B report will include an EPA
report addressing the availability and
extent of NOX controls. The section 185B
report will also provide EPA
perspectives on key ozone control
strategy issues addressed by the
National Research Council, emphasizing
the NOX issues as directed by section
185B.
1.6 Section 182(f) Demonstration
Section 182[f) outlines a process and
conditions under which the NOX NSR
and RACT requirements would not
apply. These provisions are found in
section 182(0. paragraphs (1) and (2).
Section 6 of this supplement to the
General Preamble provides general
information regarding the circumstances
under which the NSR and RACT NOX
requirements would not apply. The EPA
is preparing a separate guideline
document to further detail these
provisions.
1.7 Attainment of the Ozone NAAQS
In certain areas, a State may require
NOX controls more restrictive than those
provided by the NSR and RACT
provisions under section 182(f). Section
182(b)(l)(A), for example, requires the
State to submit a plan that provides for
specific annual reductions in emissions
of VOC and NOX "as necessary to attain
the national primary ambient air quality
standard for ozone by the attainment
date applicable." The requirement for
specific annual reductions would not
apply as to NOX reductions for those
areas for which the Administrator
determines that additional reductions of
NOX would not contribute to attainment
(section 182(b)(lJ(AXi)).
2. Applicability and Due Dates for NSR
and RACT Rules
2.1 Marginal Ozone Nonattainment
Areas
The section 182(f) NOX provisions for
NSR apply to all ozone nonattainment
areas with a classification of marginal
or higher. The RACT provisions do not
apply to marginal ozone nonattainment
areas except in ozone transport regions.
Section 182(f), read in conjunction
with the section 182(a)(2)(C) and other
NSR related provisions in section 182,
requires State NSR plans to apply to
major stationary sources of NOX, the
same requirements that govern major
stationary sources of VOC emissions (as
defined in sections 302 and 182 (c), (d).
and (e)) in ozone nonattainment areas
and in other areas located in ozone
transport regions. Section 182(a)(2)(C)
requires States to adopt and submit
revised NSR regulations for all ozone
nonattainment areas classified as
marginal or above which incorporate (1)
the new provisions of the amended CAA
and (2) correct existing regulations to
incorporate all NSR provisions in effect
immediately before the dale of
enactment. The statutory NSR permit
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55622 Federal Register / Vol. 57. No. 228 / Wednesday. November 25. 1992 / Proposed Rules
requirements for ozone nonattainment
areas are generally contained in the Act
under section 172(c)(5), revised section
173, and in various provisions spread
throughout newly enacted subpart 2 of
part D. These are the minimum
requirements that States must include in
an approvable SIP.
2.2 Moderate, Serious, Severe and
Extreme Ozone Nonattainment Areas
The section 182(f) NOX provisions for
NSR and RACT apply in all ozone
nonattainment areas classified
moderate or higher.
2.3 Ozone Transport Region
The section 182(f) NO,, provisions for
NSR and RACT apply throughout an
ozone transport region. That is, areas
designated as attainment/unclassified,
as well as ozone nonattainment areas,
must meet the NSR and RACT
requirements for NOX.
Section 176A allows the
Administrator to establish a transport
region covering multiple States
whenever interstate transport of
pollutants contributes significantly to
violations of NAAQS. Section 184(a)
sjpec.fically created at enactment by
operation of law an ozone transport
region comprising the States of
Connecticut, Delaware, Maine,
Maryland, Massachusetts, New
Hampshire, New Jersey, New York,
Pennsylvania, Rhode Island, and
Vermont, and the Consolidated
Metropolitan Statistical Area that
includes the District of Columbia.
Section 184(b) contains the specific
requirements for States in ozone
transport regions. If other ozone
transport regions are established under
section 176A, States in these regions
must also adopt and implement these
controls.
Section 184[b)(2) requires major
sources of VOC in ozone transport
regions to be subject to the same
requirements that apply to major
sources in ozone areas classified as
moderate (section 182(b)). Thus, the
State must adopt rules to apply the NSR
and RACT provisions for ozone to major
VOC sources Statewide, unless a
portion of the State has been excluded
from the transport region under section
176(a)(2). Section 182(f) specifies that
the subpart 2 provisions applicable to
VOC major sources shall also apply to
NOX mayor sources. Therefore, section
182(f) requires that the RACT and NSR
provisions be applied to major NOX
sources throughout the transport region.
2.4 Major Stationary Source
2.4.1 Ozone Nonatlainment Areas
Section 182(f] specifies lhal major
stationary sources of NOX are to be
defined according to the definitions in
sections 302 and 182(c). (d), and (e). In
ozone nonattainment areas these
definitions for NOX are the same as for
VOC and, as such, vary from 10 to 100
tons per year according to the
classification of the ozone
nonattainment area. In addition, the
same offset ratios that apply to major
VOC sources apply to major NOX
sources. For further information on these
definitions, refer to the April 16,1992
General Preamble.
2.4.2 Ozone Transport Regions
The EPA believes that the section
lS4(b)(2) provision providing that a
major stationary source is one with a
potential to emit at least 50 tons per
year is specifically limited to VOC
sources because section 182(f) does not
refer to the section 184 definition in
describing the major stationary source
definitions applicable for NO* purposes.
For portions of an ozone transport
region designated attainment/
unclassified, a major stationary NOX
source is defined by section 302(j) as 100
tons per year. Therefore, for purposes of
applying section 182(f) requirements to
NOX sources in ozone attainment/
unclassified areas in the ozone.transport
region, as well as in marginal and
moderate ozone nonattainment areas, a
major stationary source for NOX will be
defined as any stationary source that
emits or has the potential to emit 100
tons per year or more of NOX.
In the case of serious, severe, or
extreme ozone nonattainment areas
within the transport region, the lower
threshold definitions of major stationary
source and other NSR requirements
apply to NOX sources. Also, State rules
must ensure that NOX offsets [as with
VOC offsets) will be consistent with any
State or regional attainment strategies.
2.5 Genera} Due Dates for NSR and
RACT Rules
2.5.1 NSR
The amended CAA requires States to
adopt SIP revisions subject to EPA
approval that incorporate the new
preconstruction permitting requirements
for new or modified sources that were
discussed in the preceding sections.
New rules for ozone nonattainment
areas must be submitted by November
15,1992. The EPA has previously
announced its interpretation that the
new NSR requirements did not go into
effect with passage of the 1990 CAA
Amendments, but rather become
effective in accordance with the
schedule for State adoption of SIP
revisions. For further information, refer
to the April 16,1992 General Preamble
to title I, appendix D.
2.5.2 RACT
Section 182(b}(2) requires submittal of
RACT rules for major stationary sources
of VOC emissions (not covered by a pre-
enactment control techniques guideline
(CTG) document or a post-enactment
CTG document) by November 15,1992.
There were no NOX CTGs issued before
enactment and EPA has not issued a
CTG document for any NO* sources
since enactment. As discussed in § 2.6.2.
States, in their RACT rules, will be
expected to require final installation of
the actual NOX controls by May 31,1995
from those sources for which
installation by that date is practicable.
2.5.3 Ozone Transport Region
States within the Northeast ozone
transport region established by section
164(a) must revise their SIPs to include
the NRS and RACT measures by
November 15,1992. In the case of a State
subsequently included in a transport
region under section 176A, the measures
must be submitted within 9 months of
the area's inclusion in a transport
region.
Because States in a transport region
are generally subject to the moderate
area requirements, EPA believes that the
schedule for implementing these RACT -
rules in the ozone transport region
should be consistent with the
requirements of section 182(b)(2).
Therefore, States, in their RACT rules,
will be expected to require final
installation of the actual NOX'controls
by May 31,1995 from those sources for -
which installation by that date is
practicable.
2.6 Alternative Schedules for NO*
RACT Rules
2.6.1 Section 110(k) Conditional '•
Approval
Under section 110(10(4), the
Administrator may approve a plan *
revision based on a commitment by the..
State to adopt specific enforceable
measures by a specified date but not
later than 1 year after the date of EPA -'
approval of the plan revision that j
incorporated that commitment. If EPA ••
finds that the State fails to meet the *
commitment within that period, the
conditional approval would be .• '••'-
converted into a disapproval. The tin»"
periods culminating in imposition of V
sanctions and/or Federal - •
implementation plans (FIPs). pursuant h
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Federal Register / Vol. 57. No. 228 / Wednesday. November 25. 1992 / Proposed Rules 55623
sections 179 and 110(c). respectively, do
not begin to run until the conditional
approval is converted to a disapproval.
Section 182(f) provides States an
opportunity to demonstrate to EPA that
some or all of the new NOX
requirements should not apply. The EPA
has determined that, as a technical
matter, photochemical grid modeling is
the only reliable tool to justify an
areawide exemption from the NOX
requirements (or relaxation of otherwise
required NO* reductions). Therefore,
States must include in such
demonstrations photochemical grid
modeling analyses that consider various
control strategies with and without NOX
reductions. For a variety of ozone
nonattainment areas, however,
photochemical grid modeling either has
not been utilized previously.or, if
utilized, has not adequately considered
the effects of NOX emissions reductions.
The EPA recognizes that, while efforts
to conduct photochemical grid modeling
are underway in many States, the time
needed to establish and implement a
modeling protocol and to interpret the
model results will, in a variety of cases,
extend beyond the November 15,1992
deadline for submission of NOX rules.
Because Congress clearly intended to
allow States the opportunity to show
that they qualify to opt out of (or
specifically tailor) the new NOX
requirements and because modeling is
necessary to reliably determine whether
NOX emission reductions will contribute
or be counterproductive to achievement
of ozone attainment, a State could, as a
means of meeting the November 15,1992
deadline for submittal of NOX RACT
rules, submit under section 110(k)(4) a
commitment to adopt the NOX RACT
rules no later than one year after the
date of EPA approval of the
commitment. Decisions to grant
conditional approval will be made by
EPA on a case-by-case basis, and will
be limited to instances where the State
documents that (1) credible
photochemical grid modeling is not
available or did not consider the effects
of NOX reductions and (2) the State
submits progress reports on the
modeling showing the program is on
schedule while the committal SIP is
being reviewed by EPA. The committal
SIP will be disapproved if the modeling
activities are not well underway as of
the tjate of EPA final action. The
committal SIP must also require the
State to adopt NOX RACT rules
according to a specific schedule and
within one year of EPA approval.
2.6.2 Phase-in of Controls Beyond May
199S
As discussed above, the statute
requires the implementation of RACT as
expeditiously as practicable but no later
than May 31.1995. Depending on the
source category, the number of
potentially affected sources ranges from
tens to thousands. In the past, NOX
controls for older sources were not
required on a national scale and, thus,
control equipment manufacturers have
not supplied NOX controls at the rate
needed to meet the May 31.1995
deadline. It is possible, therefore, that
the control equipment will not be
available in all cases to meet the
demand. As described in more detail
below, if a State demonstrates that
installation of all controls by May 31.
1995 is not practicable for all the
affected sources, for example, due to
equipment unavailability or system
reliability. EPA would consider
approving rules that define RACT as a
phased program extending beyond that
date for those sources for which the
application of the controls by May 31.
1995 is impractical.
States, in their RACT rules, will be
expected to require final installation of
the actual NOX controls by May 31.1995
from those sources for which
installation by that date is practicable.
For the remaining sources, the rule
should define RACT itself as a stage-by-
stage program of measures, ranging.
perhaps, from preliminary set-up
measures in the first year or so to fully
installed and operating control
equipment as the end-stage. The rule
must also include clearly specified
compliance milestones that represent
the most expeditious schedule
practicable toward final compliance.
Under this approach, the portion of the
schedule that can practically be
implemented by May 31,1995. must be
implemented by that date and the other
portions of the schedule leading toward
(and including) final installation of
controls must be implemented as soon
as those steps become practicable {and
hence will supplement the initial RACT
at those later times). Further, given the
need for many moderate nonattainment
areas to demonstrate attainment by
1996. States should make every effort to
ensure that the actual controls for any
source which causes or contributes to a
moderate area's nonattainment status
are installed prior to the 1996 ozone
season.
2.7 Section 182(f) Demonstration
The NSR and RACT provisions for
NOX described above do not apply in
those areas for which the Administrator
makes a determination, pursuant to
section 192(f) (1) or (2), that all or some
of the NO* provisions are not required.
Refer to section 6 of this document for
further information.
3. New Source Review
3.1 General NSR Requirements
The NSR requirements are detailed m
section III.G of the General Preamble to
title I. The NSR provisions include, but
are not limited to. requirements that a
new or modified major stationary source
will apply controls representing lowest
achievable emission rate (LAER) and
that the source will obtain an emission
offset prior to operation. Unless
otherwise noted, the requirements
detailed in section Hl.G of the General
Preamble to title I for major VOC
sources must also be applied for major
NOX sources.
3.2 NSR in Submarginal Areas
Nonclassified ozone areas consist of
transitional, submarginal, and
incomplete/no data areas. As described
in section III.A.7 of the General
Preamble to title I. all nonattainment
areas, including submarginal,
transitional and incomplete/no data
areas, are required to adopt NSR
programs meeting the requirements of
section 173 as amended. However, the
NOX requirements of section 182(0 do
not apply in these areas for ozone,
except in the ozone transport region
This is because section 182[f) applies
only to those NOX sources located in
areas subject to requirements of subpart
2 of part D of title I. That group consists
only of sources located in the ozone
transport region per section 184 and in
areas classified under Table 1 of section
IBl(a), which does not include the
submarginal and incomplete/no data
areas located outside the transport
region.
3.3 NSR in Marginal Areas
Marginal areas outside of the ozone
transport region that expect to attain by
November 1993 might not realize a
benefit from NOX NSR requirements due
to the lag time between regulation
adoption and implementation within a
source. Adoption of NSR rules by
November 1992 would provide a 1 year
period where new or modified sources
would be subject to the rules. In
contrast, even with an approved
preconstruction permit, construction and
startup of major new sources or major
modifications may take 1 to 2 years, or
more, depending on the complexity and
size of the project. Thus, any emission
benefit from offsets or avoided emission
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55624 Federal Register / Vol. 57, No. 228 / Wednesday, November 25, 1992 / Proposed Rules
increases rr.ighl not be realized until
well after the attainment deadline.
As described in section 6 of this
supplement to the General Preamble, if
specific NOX reductions do not
contribute to attainment, States may
request an exemption from the NOX
requirements under Ihe section 182(f)(2)
excess reductions provision. However, if
these areas obtain such an exemption
based on the limited effect of NOj
reductions between 1992 and 1993, but
then do not aV.a'.n by the end of 1993,
these arpos would then be subject to the
nonattair.menf NSR requirements of the
CAA dnd would need a pre-cor.s(ruction
permitting program to meet these
require'nents.
Alternatively, Slates could apply the
full range of NSR requirements to
prospective new or modified major
sources for which complete permit
applications are submitted after
November 15, 1992. Because of the lead
time involved, it is unlikely that many
such sources will have received permits
and made substantial investments in
LAER controls prior to the November
1993 marginal area attainment date. At
that time, if the area has achieved
attainment and meets EPA
redesignation criteria, the State could
request redesignation and, following
approval, the State permit program
could be revised to delete any
superfluous requirements.
3.4 VOC and NO* Emissions
The EPA finds nothing in the statutory
language to suggest that emissions of
VOC and NO* are to be added together
for part D NSR applicability purposes.
That is, VOCs and NOX are to be
considered separately for purposes of
determining whether a source is subject
to the permit requirements.
3.5 Prevention of Significant
Deterioration (PSD)
Because NOX emissions also
contribute to ambient concentrations of
nitrogen dioxide, for which a NAAQS
has been set, the PSD provisions of part
C apply to major stationary sources of
NOX in all areas designated attainment
or unclassifiable for nitrogen dioxide.
Further, as described in section 3 of this
supplement, NOX NSR is required in
certain ozone nonattainment areas and
the ozone transport region. In many
areas, both the nonattainment NSR and
the PSD requirements apply. The major
stationary source thresholds defined in
the PSD rules continue to apply when
deteTminfng PSD applicability. Where a
source mint meet both the LAER and
Best Available Control Technology
JBACT) requirements for NOx. the more
etringent LAER requirement satisfies the
BACT requirement.
3.6 NSR Offset Commitment
Some sources have expressed the
concern that the delay in adopting
RACT rules for utility boilers and other
stationary sources may hinder efforts by
new or modifying NOX sources to secure
offsets. Their fear is that the uncertainty
over the eventual RACT limit may lead
existing NOX stationary sources—the
easiest source of offsetting credits—to
retain for their own use otherwise
surplus NOx emissions reductions. Thus,
until RACT levels are established, there
may be a scarcity of NO* offsets
available to fund growth in these
nonattainment areas. For this reason,
EPA will approve NSR SIP revisions
which require NOX offsets for new and
modifying sources in ozone
nonattainment areas, but which allow
sources to secure the offset at any time
up until the source commences
operation. By delaying the offset
requirement through the construction
period, States will allow sources more
time to secure offsets and, thus, enabling
sources to wait out any initial
uncertainties with the NOx emissions
reduction market.
Under existing EPA policy, sources
must identify and secure offsetting
emissions reductions as a condition for
receiving a new source review
preconstruction permit. See 40 CFR
51.165, appendix S. Most States have
incorporated this requirement into their
nonattainment preconstruction review
program by requiring the offset to be in
effect and secured by a federally
enforceable permit condition prior to the
issuance of the permit to construct the
modification or new source. However,
the amended CAA is not so restrictive.
Section 173(a) states that offsetting
emissions reductions must be "federally
enforceable before {the NSR] permit
may be issued." However, both sections
173(a)(l) and (c) explicitly state that the
offsetting emissions reductions only
need to be in effect by the time a new or
modified source "commences
operation." If States wish to take
advantage of this statutory language and
issue permits to sources on the basis of
an enforceable commitment to secure
the offset by the time the source is ready
to commence operations, EPA will not
object. However, EPA will require that
permits issued in this manner contain
federally enforceable provisions that
expressly prohibit the commencement of
any actual operations until such time as
the necessary offsetting emissions
reductions have been identified,
approved, and secured with appropriate
permit restrictions on the source
providing the restriction.
4. Reasonably Available Control
Technology
4.1 Background
On a nationwide basis, stationary
source NOX emissions originate
primarily from four types of sources:
Utility boilers, gas turbines, internal
combustion engines, and industrial
boilers. Approximately 85 percent of
stationary source NOX emissions are
accounted for by these aources, wi'.h
utility boilers contributing almost 60
percent of the total stationary source
emissions. Other source categories can
be important in individual areas.
Section 182(b) refers to CTGs and
CTG documents that have been or will
be developed to assist in the
determination of RACT for several
categories of VOC sources. However.
neither CTG documents nor CTGs
themselves have been issued for NO*
sources and the CAA does not require
NO, CTGs.
4.2 General Definition of RACT
The EPA has defined RACT as the
lowest emission limitation that a
particular source is capable of meeting
by the application of control technology
that is reasonably available considering
technological and economic feasibility
(44 FR 53762; September 17,1979).
Although EPA historically has
recommended source-category-wide
presumptive RACT limits, and plans to
continue that practice, decisions on
RACT may be made on a case-by-case
basis, considering the technological and
economic circumstances of the
individual source. The EPA will make
data from NO, RACT determinations
available through a clearinghouse
required by section 108(h).
RACT may require technology that
has been applied to similar, but not
necessarily identical, source categories.
Presumptive RACT limits are based on
capabilities which are general to an
industry, but may not be attainable at
every facility.
An extensive research and
development program should not be
necessary before a RACT control
technology can be applied to a source.
This does not, however, preclude
requiring a short-term evaluation
program to permit the application of a
given technology to a particular source.
4.3 Relation to ACTs
Section 183(c) requires the
Administrator to issue alternative
control technique documents (ACTs) by
November 1993 that identify alternative
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Federal Register / Vol. 57. No. 228 / Wednesday. November 25. 1992 / Proposed Rules 5562
controls for all categories of stationary
sources of VOCs and NOX that emit
more than 25 tons per year. Through the
ACT documents. EPA will provide
information on the full range of NOX
control technologies for categories of
stationary sources that emit or have the
potential to emit 25 tons per year or
more of NO*.
Similar to the CTGs issued for VOC
source categories, the ACTs will contain
extensive background information on
control technologies, costs, availability.
etc.. that can be used by States in
making RACT determinations. However,
unlike the CTGs, the ACTs will not
established a presumptive RACT.
4 4 Relation to Title IV
Coal-fired utility boilers located in
nonattaiiunent areas must meet the NOX
RACT requirements of section 182(f), as
well as any other applicable
requirements of title 1 of the Act, and the
NOX requirements of section 407 under
the acid rain program in title IV of the
Act. The NOX RACT requirements for
certain electric utility-boilers are
discussed in 5 4.6 of this document. As
required under section 407, EPA will
promulgate regulations to limit
emissions from coal-fired boilers.
Utilities should plan to meet the most
stringent requirements applicable under
the Act.
4.5 Relation to VOC RACT Policies
Over the last 15 years, EPA has
provided guidance on what constitutes
RACT for stationary sources. During
these years considerable information
and definitions have been.provided by
EPA concerning RACT. While this
guidance has been largely directed at
application within the VOC program.
much of the guidance is also applicable
to RACT for stationary sources of NOX.
4.6 RACT for Certain Electric Utility
Boilers
The EPA has determined that, in the
majority of cases, RACT will result in an
overall level of control equivalent to the
following maximum allowable emission
rates (pounds of NOX per million Btu) for
utility boilers:
(a) 0.45 for tangentially fired, coal
burning;
(b) 0.50 for dry bottom wall fired
(other than cell burner), coal burning:
(c) 0.20 for tangentially fired, gas/oil
burning, and
(d) 0.30 for wall fired, gas/oil burning:
Compliance with these limits may be
determined on a continuous basis
through the use of a 30 day rolling
average emission rate, calculated each
operating day as the average of all
hourly data for the proceeding 30
operating days. As described below.
EPA believes that the above emission
rates are appropriate for application to
groups of boils on an areawide average.
Btu-weighted basis.
The EPA expects States, to the extent
practicable, to demonstrate that the
variety of emissions controls adopted
are consistent with the most effective
level of combustion modification
reasonably available for its individual
affected sources. However. EPA
encourages States to structure their
RACT requirements to inherently
incorporate an emissions averaging
concept (i.e.. installing more stringent
controls on some units in exchange for
lesser control on others). Therefore, in
the interest of simplifying State RACT
determinations and enhancing the
ability of States to adopt market-based
trading systems for NOX, the State may
allow individual owners/operators in
the nonattainment area (or,
alternatively. Statewide within an ozone
transport region) to have emission limits
which result in greater or lesser
emission reductions so long as the
areawide average emission rates
described above are met on a Btu-
weighted basis.
In general, EPA considers RACT for
utilities to be the most effective level of
combustion modification reasonably
available to an individual unit. This
implies low NOX burners, in some cases
with overfire air and in other instances
without overfire air flue gas
recirculation; and conceivably some
situations with no control at all. The
actual NOX emission reduction that can
be achieved on a specific boiler depends
on a number of site-specific factors
including, but not limited to. furnace
dimensions and operating
characteristics, fuel type and
characteristics, design and condition of
burner controls, design and condition of
stream control systems, and fan
capacity. The combustion modification
technology must be custom-designed for
each boiler application. The ease of
retrofitting varies substantially from one
boiler to another. Combustion
modifications may also include: Low
excess air. biased burner firing, burners
out of service, reduce air preheat, and
steam/water injection.
4.7 RACT for Other Utility Boilers and
Source Categories
For source categories and utility
boilers other than the electric utility
boilers specified above, EPA is not
recommending a specific RACT level in
this document. In general. EPA expects
that NO» RACT for these other sources
will be set at levels that are comparable
to the RACT guidance specified above
for certain electric utility boilers.
Comparability shall be determined on
the basis of several factors including, fc
example, cost, cost-effectiveness, and
emission reductions.
4.8 Enforceability
The SIP measures must be converted
into a legally-enforceable vehicle (e.g., t
regulation). The regulations or other
measures must meet EPA's criteria
regarding the enforceability of SIPs and
SIP revisions. Guidance on
enforceability requirements has been
provided to Regional Offices in various
memoranda (see Bauman/Biondi and
Potter/Adams/Blake memoranda listed
in Section III.D.6. of the General
Preamble to title I).
In cases where States adopt an
areawide averaging rule for a group of
sources, the emission limits, emission
quantification methods, and monitoring
and recordkeeping requirements
applicable to each owner/operator in
the group must be clearly specified. In
addition, the rule must specify
appropriate penalties for violation of th<
various requirements.
5. Emissions Trading and Economic
Incentive Programs
5.1 Emission Trading Policy Statement
Since 1976 EPA has developed severa
emissions trading programs to allow
industry and States more flexibility in
meeting statutory requirements of the
Clean Air Act. The bubble, offset,
netting and banking programs, discusse<
in EPA's Emissions Trading Policy
Statement (ETPS) (51 FR 43812,
December 4,1986) each entail the
creation, storage and/or use of emission
reduction credits. Only emission
reductions which are surplus,
quantifiable, federally, enforceable, and
permanent may be used in an emissions
trade
5.2 Economic Incentive Programs
The EPA encourages the development
of economic incentive programs (EIPs)
that increase flexibility and stimulate
the use of more cost-effective control
strategies while providing incentives to
develop and implement innovative
emission reduction technology and
strategies beyond those specifically
mandated through standards and
regulations. The use of economic
incentives is explicitly allowed for in the
general SIP requirements (section
110(a)(2)(A)). the general provisions for
nonattainment SIPs (section 172(c)(6)).
and the system of regulations for
controlling emissions from consumer
and commercial products (section
183(e)(4)). Beyond these general
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55626
Federal Register / Vol. 57. No. 228 / Wednesday. November 25. 1992 / Proposed Rules
authorities, the use or consideration of
an economic incentive program is
mandated in certain cases. Section
182(g) of the CAA calls for EPA to
publish economic incentive rules for
mandatory EIPs by November 15,1992.
It is expected that the EIP rules (which
will also serve as EPA's guidance for
discretionary programs) will be broadly
applicable to any type of EIP, and will
provide flexibility to States in the
development of market-based,
innovative programs for stationary,
area, and mobile sources. The EIP rules
will require EiPs submitted by States to
EPA for approval as part of a SIP to
contain design features that will ensure
that (1) emissions reductions credited to
the program will be quantifiable and
consistent with SIP attainment and
reasonable future progress
demonstrations, as applicable; (2) any
credited emissions reductions will be
surplus to reductions required by, and
credited to, other implementation plan
provisions to avoid double counting of
reductions; (3) programs are federally
enforceable and credited reductions will
be permanent within the timeframe
specified within the program; and (4] no
interference with other requirements of
the CAA will occur. The proposed rules
will identify key program provisions
which must generally be included to
ensure that tha above requirements will
be met. However, it is not expected that
the rules will limit flexibility and
innovation beyond those constraints
thai are necessary to meet these
requirements.
5.3 Geographic Limitations
Offset programs should be subject to
tije geographic limitations contained in
section l"3(c)(l] for new or modified
major slai;onary sources. Section
!73{c](i] stipulates that emissions
offsets generally must be obtained by
the same sc-jrce or other existing
sources in the same nonattainment erea.
However, the statutory provision does
allow offsets to be obtained in another
nonattainment area under two specific
conditions.
First, the other nonattainment area
must have an equal or higher
nonattainment classification than the
nonattainment area in which the source
would construct. In applying this
provision, the other nonattainment area
must have an equal or higher
nonattainment classification for the
same pollutant. For example, a proposed
major new source of NO, seeking to
locate in a nonattainment area classified
as Serious for ozone could possibly
obtain emission offsets in another ozone
nonattainment area if such area were
designated Serious, Severe or Extreme
for ozone.
The second condition is that the
emissions from such other
nonattainment area must contribute to a
violation of the NAAQS in the
nonattainment area in which the source
would construct. The showing that such
contribution from sources in another
nonattainment area exists should be
acknowledged and verified by the
permitting authority.
5.4 Relation to Title IV Required
Reductions
Section 407 of title IV of the Clean Air
Act requires the EPA to establish annual
average NOX emission limits for certain
electric utility boilers and allows the
averaging of emissions between affected
biolers in order to meet the emission
limits as a group. NO, emission
reductions at these utilities which result
from the title I program may be used for
purposes of meeting the title IV NO,
requirements. Further, as discussed
below, NO, emission reductions
resulting from the title IV program may
be considered for purposes of meeting
certain title I requirements, under
appropriate conditions.
To receive title I SIP credit for use
under an EIP or for purposes of banking,
bubbling, or netting, emission reductions
from the title IV program must be
surplus to the title I requirements,
enforceable, quantifiable, and
permanent. Only those title IV emission
reductions that exceed any applicable
title 1 requirements (e.g., RACT) would
be surplus. To be enforceable for title I
purposes, the title IV emission
reductions must be part of an approved
SIP or federally enforceable operating
permit. To be quantifiable for title I
purposes, emission reductions must be
measurable or predictable on a
timeframe appropriate for the purposes
of title I, generally one hour or twenty-
four hour levels on a typical high ozone
day. Emission reductions at title IV
bo
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Federal Register / Vol. 57. No. 228 / Wednesday. November 25. 1992 / Proposed Rules 53
will accept or reject the demonstration
as part of the rulemaking process on the
accompanying SIP revision.
The EPA's decision will be based on
the demonstration provided by the State
and application of the guidance
contained in the relevant EPA
document. The EPA encourages the
States to consult with the appropriate
EPA Regional Office during the
development of the documentation and
plan revision. This is necessary to
ensure that the documentation provided
by the State is hkely to be approved and
that any required rules can be adopted
in a timely manner.
Section 182(p(3) also provides that a
person (including a State) may petition
the Administrator for a NO, exemption
at any time after the final section 185B
report is submitted to Congress. The
petition may be made with respect to
any nonattainment area or any portion
of an ozone transport region. The EPA is
required to grant or deny a petition
within 6 months. The EPA's decision
will be based on the documentation
provided by the petitioner, the State's
recommendation, and application of the
EPA guidance. The EPA does not intend
to delegate this authority to the States.
As noted above, the petitions may be
submitted to EPA after the final section
185B report » sent to Congress. The
Section 185B report must be prepared by
EPA, in conjunction with the National
Academy of Sciences, and was
mandated by Congress In order to
improve understanding of many aspects
of the roles of NO> and VOC in ozone
formation. Section 182(f) requires EPA,
in its review of a petition, to "consider
the study required under section 185B."
Thus, the petition opportunity is linked
to consideration of a portion of the
section 185B study. EPA is preparing a
separate guidance document to
specifically describe acceptable
methods to demonstrate cases where an
exemption from the NO* requirements is
appropriate (exemption guidance). The
exemption guidance includes
consideration of the National Academy
of Sciences portion of the section 183B
study. Further, in formulating the
exemption guidance. EPA will address
relevant issues that are being examined
in the section 185B study, in particular.
the extent to which NO* reductions may
contribute (or be counterproductive) to
achievement of attainment in different
ozone nonattainment areas.
While the amended CAA provides a
person the opportunity to petition EPA
under section I82(f)(3) after EPA
submits the section 185B report to
Congress, the statute also mandated the
submittai of the report to Congress by
February 15,1992. In this sequence of
events. Congress dearly intended that
petitions could be submitted to EPA well
before the November IS, 1992 statutory
deadline for adoption of the NOX rules
by States. In fact, the report was not
provided to Congress within the
intended timeframe and, therefore.
major stationary sources could be
subject to the NO, rules without an
opportunity to demonstrate through the
petition process that the rules should not
apply. EPA does not believe that
Congress intended this result In any
event, section 182(0(3) indicates that the
Administrator may consider and act on
petitions after submission of the section
185B report to Congress. That language
prescribes a specific time after which
the Administrator must make the
required petition determinations.
However, nothing in that section
expressly prohibits the Administrator
from exercising his discretion and
considering a petition prior to
submission of the report to Congress, so
long as the Agency considers, in its
review of the petition, the relevant
issues examined by the section 185B
study. Therefore, EPA has decided to
act. within 8 months of receipt, on any
petition under section 182(f)(3} that is
received after the issuance of EPA's
exemption guidance. In light of these
unforeseen circumstances, EPA believes
this solution best implements what
Congress originally intended.
Since there may be multiple petitions
for a given area and the SIP is primarily
a Slate responsibility, a copy of any
petition (other than from the State itself)
should be provided to the Stale at the
same time it is submitted to the
Administrator. The EPA will provide the
State a 3-month period to provide a
recommendation to EPA regarding the
area. This 3-month period runs
concurrent with the required 6-month
period noted above. A copy of the
petition should also be submitted to the
relevant EPA Regional Office and EPA's
Office of Air Quality Planning and
Standards.
The EPA encourages any petitioner to
consult with the State air quality agency
and the appropriate EPA Regional
Office during the development of a
section 182(f) demonstration. This is
necessary to ensure that the
documentation provided (1) meets EPA
guidance, (2) does not conflict with
similar analyses by the State, and (3) is
Hkely to be accepted by the State and
EPA. The EPA's decision would be
based on the demonstration provided by
the petitioner, the State's
recommendation, and application of
EPA guidance.
If EPA grants a petition, some or all of
these title 1 NO, requirements would no
longer apply. However. States remain
free to impose NOX restrictions on oth
bases. For example. States may choos
in certain circumstances to reduce NC
emissions for purposes of ozone
maintenance planning, visibility
protection, PM-10 control, acid
deposition control or other
environmental protection. If. however,
the EPA finds that NO» reductions are
counterproductive to the extent that, fi
example, they delay ozone attainment
the State would have to justify how thi
SIP continues to be adequate for
achieving ozone attainment given its
NO> reductions. That is because the
statute does not permit EPA to approvi
a SIP revision that would "interfere
with" meeting any requirement of the
Act {section 110(1]).
6.3 Ozone Transport Region
Attainment/Unclassified Areas
The Act does not clearly state
whether or not portions of a transport
region that are attainment/unclassified
can opt-out of the NO* requirements.
The section 182(f)(l)(B) exemption
provision specifically applies only to
nonattainment areas within a transport
region. The section 182(f)(l) net air
quality benefit test is available to any
area; however, it is a high hurdle and
this is especially true in rural areas.
Thus, while a severely polluted area
might be able to avoid NOX reductions,
the Act could be interpreted to require
NO> reductions in the surrounding
attainment area.
An alternative reading of the Act can
be found under section 184(b)(2). This
provision states that the attainment/
unclassified portions of the transport
region must meet "the requirements
which would be applicable to major
stationary sources if the area were
classified as a moderate nonattainment
area." Thus, the Act could be
interpreted to provide the same section
182(f)(l)(B) exemption process for these
attainment/unclassified areas, since
they would be treated as moderate
nonattainment.
It is unlikely that Congress intended
more stringent requirements for the
attainment/unclassified portions of an
ozone transport region than would apply
to the more severely polluted portions.
Therefore, EPA interprets the section
182(f)(l](B) provision to apply to any
portion of an ozone transport region.
6.4 Relation to the SIP
Where a petition for an exemption
(section 182|f)|l)) or excess reductions
determination (section 182(0(2])«
granted by EPA prior to adoption and
submittal of the State's rules, the State
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55628 Federal Register / Vol. 57. No. 226 / Wednesday, November 25, 1992 / Proposed Rules
may simply choose not to submit the
rules. If a petition is granted after
submitta! of the rules, but prior to EPA
approval, the State may choose to
withdraw the rules and preclude further
EPA action In a case where a petition is
granted ("exempted area") after EPA
approves of the NOX rules, the SIP
would need to be modified to rescind
the NOX rules. In an exempted area, the
NOX RACT and/or NSR rules may be
rescinded at any time through a SIP
revision, provided such rescission would
not interfere with attainment or
reasonable further progress (section
110(13).
Following application of a
photochemical grid model that is
required for serious and above areas to
support the attainment demonstrations
due by November 1994. a State must
select and adopt a control strategy that
provides for attainment as expeditiously
as practicable, but no later than the date
prescribed in section 181. This decision
must be addressed by a State whether
or not an area was exempted from the
November 1992 submittal of NOX RACT
and/or NSR rules and may result in
revision of the previously adopted rules.
In some instances the NO* RACT and
NSR requirements already adopted may
need to be supplemented with
additional or more advanced NOX
controls in order for the area to attain
the NAAQS.
In other cases, an area initially
exempted may choose, based on the
new photochemical grid modeling
results, to adopt certain NOX reduction
rules in order to attain and/or meet
reasonable further progress
requirements through NOX substitution.
The area would be removed from
"exempt" status since NOX reductions
were subsequently found to be
beneficial in their ozone attainment
plan. Consequently, the area would have
to adopt the NOX RACT and NSR rules
except to the extent modeling shows
that the controls bejond those chosen
are "excess reductions." Credit for NOX
substitution would be granted only if in
accordance with the EPA guidance. In
any event, these changes must be
submitted as a SIP revision and must
provide for attainment as expeditiously
as practicable and meet reasonable
further progress requirements.
Alternatively, for an area that
adopted the NOX RACT and NSR rules
as required by section 182 (i.e., not
exempt), a State may choose to revise
some or all of those rules to require less
NOX stationary source controls. This
action would be based on the
application of a photochemical grid
model showing that the subject NOX
controls result in excess emission
reductions, as determined using the
section 182(f) tests set forth at the
beginning of this section. The revisions
must be submitted as a SIP revision and
the S!P must demonstrate attainment as
expeditiously as practicable.
7. Control Technology Information
7.1 Alternative Control Technique
(ACT) Documents
Section 183(c) requires the
Administrator to issue ACT documents
by November 1993 that identify
alternative controls for all categories of
stationary sources of VOCs and NOX
that emit more than 25 tons per year.
Through the ACT documents. EPA will
provide information on the full range of
NOX control technologies for categories
of stationary sources that emit or have
the potential to emit 25 tons per year or
more of NOX. While the ACT documents
will not contain presumptive RACT
emission limits, they will contain
extensive background information on
control technologies, costs, etc., that can
be used by States in making RACT
determinations. The EPA will issue ACT
documents for specific source categories
as they are completed.
7.2 Section 185B Report
The report required by section 185B
will include information on the
availability and extent of controls for
NOV
7.3 Section 108(h) Clearinghouse
Under section 173(d). the States must
provide that the control technology
information from permits issued under
section 173 be promptly submitted to
EPA's RACT/BACT/LAER
clearinghouse, to other States, and to the
general public.
6. NOX Reductions Needed to Attain the
Ozone NAAQS
B.I Attainment Demonstration
As described in Sections III.A.3 and
III.A.4 of the General Preamble to title I.
States must provide a SIP for moderate
and above classified ozone
nonattainment areas that includes
specific annual reductions in VOC and
NOX emissions as necessary to attain
the NAAQS. This requirement
supplements the RACT and NSR
requirements described above. The
requirement for specific annual
reductions would not apply as to NOX
reductions for those areas for which the
Administrator determines that
additional reductions of NOX would not
contribute to attainment (section
B.2 Advanced Control Technologies
In certain areas. States may require
NOX controls based on advanced control
technologies: i.e.. control technologies
that reduce emissions beyond RACT or
title IV requirements. For example.
advanced controls would be required ax
part of a serious ozone nonattainment
area's 1994 SIP if modeling found such
controls to be necessary to provide for-
expeditious attainment of the ozone
NAAQS. In order to avoid or minimize
potentially incremental or repetitive
control requirements. States and
regulated sources should consider in
advance the implications of all relevant
requirements.
8.3 Transported Pollutants
In developing their control strategies.
States need to consider the transport of
pollutants into downwind areas and
resultant impacts on the ability of such
areas to attain the ozone NAAQS as
required. For further discussion of this
issue, refer to the General Preamble
published April 16.1992.
9. Other NOX Related Provisions in
Title 1
9.1 Contingency Measures
The contingency measures for serious
and above ozone nonattainment areas
are required by section 182(c)(9) to be
adequate to correct any shortfall in
meeting an emission reduction mikstone
(e.g., the 15 percent reduction required
by late 1996). If the strategy for an area
relies on NOX reductions in addition to
VOC reductions, the State should also
submit NOX contingency measures.
These measures are described in section
III.A.2.C. of the General Preamble to titk
I.
9.2 Rule Effectiveness
The same criteria apply for NOX as for
VOC. Refer to section IH.A.3.(a)(4] of the
General Preamble to title I.
10. Other Requirements
10.1 Executive Order 12291
Under Executive Order 12291. EPA is
required to judge whether an action is
"major" and. therefore, subject to the
requirement of a regulatory impact
analysis. The Agency has determined
that this action is exempt from
classification as "major" because it is *
compilation of interpretive rule and
general statements of policy as defined
in the Administrative Procedure Act
(APA).
10.2 Regulatory Flexibility Act
Whenever the Agency is required by
section 553 of the APA or any other law
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Federal Register / Vol. 57, No. 228 / Wednesday. November 25, 1992 / Proposed Rules 556
to publish general notice and proposed
rulemaking for any proposed rule, the
Agency shall propose and make
available for public comment an initial
regulatory flexibility analysis. The
regulatory flexibility requirements do
not apply for the NO* Supplement to the
General Preamble because it ia not a
regulatory action in the context of the
APA or the Regulatory Flexibility Act.
Dated: October 27,1992.
William K. Reilly,
Administrator.
|FR Doc. 92-275*8 Filed 11-24-92:8.45 am]
BtLUNOCOOC *MO-SO-«
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14
D-2
Questions and Answers on Nitrogen Oxides Emission Policy
(2-2-93)
On November 25, 1992, the NOx supplement to the April 16,
1992 General Preamble was published. As the States incorporated
this guidance into their rule development process, policy
questions rose. This memorandum responds to several NOx
questions involving modeling, the deadline for implementing NOx
RACT rules, and EPA policy on NOx RACT committal SIPs. It also
announces the formation of a NOx policy work group, and includes
a list of group members.
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February 2, 1993
MEMORANDUM
SUBJECT: Questions and Answers on Nitrogen Oxides (NOx)
Emissions Policy
FROM: G. T. Helms, Chief
Ozone/Carbon Monoxide Programs Branch (MD-15)
TO: Air Branch Chiefs, Regions I-X
On November 25, 1992, the NOx supplement (57 FR 55620) to
the General Preamble (57 FR 13498, April 16, 1992) was published.
As the States incorporate this guidance into their rule
development process, policy guestions have arisen.
In order to address these guestions, the various
Headguarters and Regional offices have formed a NOx policy work
group (a list of work group members is attached). In order to
disseminate the group's consensus on these guestions, I will be
issuing a series of guestions and answers. The first of these is
attached. I ask that you provide this information to the
appropriate State and local agencies in your Region. This is
intended to guide you and your States during the development of
NOx rules. It is only guidance and deviations are always
permitted so long as adeguate technical rationale is contained in
the State plan.
Staff guestions on this material may be directed to Doug
Grano at (919) 541-3292.
Attachment
cc: Air Division Directors, Regions I-X
NOx Policy Work Group Members
Kent Berry
John Seitz
Lydia Wegman
John Bachmann
Doug Grano
John Silvasi
Laurel Driver
Bill Neuffer
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Interpretation of NOx Policy
1. Q; What are the definitions of "credible" and "available"
modeling as used in section 2.6.1 of the NOx supplement to the
General Preamble?
A: "Credible" means modeling that is consistent with
Environmental Protection Agency (EPA) guidance. Application of
the urban airshed model (UAM) should be consistent with
techniques specified in the EPA document, "Guideline on Air
Quality Models (Revised)11 and related guidance. Further, for
consideration of the effects of NOx emissions reductions on the
Ozone Transport Region as a whole, "credible" modeling includes
use of EPA's "Regional Ozone Modeling for Northeast Transport"
study (June 1991). When more recent regional oxidant model
and/or UAM studies have been completed and are available, they
should be used. The EPA may, on a case-by-case basis, approve
alternate photochemical grid models following the procedures
outlined in EPA's "Guideline on Air Quality Models."
Less sophisticated models, such as Empirical Kinetic
Modeling Approach, lack the detailed treatment and consideration
of physical orientation of NOx sources and dispersion of their
plumes. Further, since trajectory models only address a limited
number of trajectories, they cannot assess whether NOx control
contributes to attainment at all locations in an ozone
nonattainment area. Therefore, such models are insufficient and
not "credible" for the section 182(f) demonstration.
"Available" means the modeling results are publicly
available for review.
2. 0: For purposes of installation of control equipment after
May 31, 1995f could a State establish the post-May 31f 1995
schedule;
- in the initial submittal of the RACT rule?
- at a later date consistent with criteria specified in the
initial RACT rule? or
- in a subsequent SIP revision?
A: As described in section 2.6.2 of the NOx supplement to
the General Preamble, if a State demonstrates that installation
of all controls by May 31, 1995 is not practicable for all the
affected sources, EPA would consider approving rules that define
RACT as a phased program extending beyond that date for those
sources. The EPA is in the process of developing guidance to
define such "impracticable" situations. The guidance below
describes the regulatory process to manage these cases.
In such cases, the rule should define RACT itself as a
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stage-by-stage program of measures which are implemented over
time. The portion of the schedule that can practically be
implemented by May 31, 1995 must be implemented by that date.
The other portions of the schedule leading toward (and including)
final installation of controls must be implemented as soon as
those steps become practicable (and, hence, will supplement the
initial RACT at those later times).
Alternatively, the State may establish criteria in the
initial or in a revised RACT rule that set a replicable procedure
for the State to determine, on a source-specific basis, where
final installation of controls may occur after May 31, 1995. The
criteria must be consistent with EPA guidance on this subject.
Replicable procedure is described in EPA's emissions trading
policy statement (51 FR 43850, December 4, 1986).
Where a State initially adopted a RACT rule that required
installation of all controls by May 31, 1995, the State could, in
cases that are consistent with EPA guidance, revise the rule at a
later time. The revised rule could allow installation of certain
controls after May 31, 1995 on a source-specific basis. Under
section 110(1), EPA could consider approval of the revision as
long as the revision provides for implementing the controls as
soon as practicable and does not interfere with reasonable
further progress or attainment.
3- Oj When should EPA approve a NOx RACT committal State
implementation plan fSIPl?
A: The NOx RACT committal SIP must be consistent with
requirements outlined in the July 22, 1992 memorandum from
Michael Shapiro to the Regional Air Directors and should include:
1. An introductory section describing the reason for the
committal SIP instead of a full SIP submittal.
2. Documentation that credible photochemical grid modeling
is not available or did not consider the effects of NOx
reductions.
3. Identification of resources to complete the
photochemical grid modeling.
4. A schedule outlining the milestones that have been and
will be achieved toward completion of the modeling
activities and the NOx RACT rules. The schedule should
include milestones and completion dates for the
following:
- completion date of the modeling protocol(s);
- completion date of modeling runs in each
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nonattainment area;
- submittal of final modeling results to EPA;
- submittal of draft NOx RACT rules to EPA for comment;
- dates for public notice and hearing on the rules; and
- date for final submittal of the rules to EPA (no
later than 12 months after EPA's final approval of the
committal SIP).
5. The sche-iule should al?o include the subnittal to EPA
of pericdic (at least quarter] y". progress reports on
the modeling and NOx RACT rule development showing that
the proqram is on schedule.
4. 0: Existing solid waste incineration units will be
regulated under se ;.* ;.r.n 129(bt cf the Clean Air Act 'Act) on a
later timeframe thar. the reascnab] y available controx technology
(RACT) requirement. Can the RACT rules be delayed in order to be
consistent with the section 129 ru^emaking?
A: Section 129 of the Act requires that NOx limits be set
for new and existir.q solid waste incinerators. Section I29(b)(2)
requires that these limits go into effect no later than 5 years
after the guidelirep are promulgated by EPA. As these guidelines
have not yet been rreposed, it is unlikely that the Guidelines
will become final ..ntil after 1S93. Thus, the section 129 NOx
limits may not be effective until sometime after 1998.
States want to avoid adopting N0>. ."^ACT limits that are
effective in 1995, "snowing that potential]'/ conflicting section
129 NOx limits may be reguired only a few years later for the
same units. This issue is similar to a general concern for any
major NOx source ;:.. teaory: the- 19^5 RACT limits might conflict
with SIP limits tn-t ere determined necessary after completion of
an area's 1994 attainment demonstration. The post-attainment
demonstration controls would be scheduled for installation
sometime prior to the attainment deadline (e.g., 1998 for serious
nonattainment areas).
A State must meet all requirements of the Act. Therefore,
EPA cannot approve a State strategy to defer the RACT requirement
so that it might coincide with control decisions under section
129; nor can EPA guarantee that a NOx RACT limit would also meet
a section 129 limit. However, it now appears that the timing of
the section 129 requirements may coincide with the tiir-irg for
installation of controls resulting from the post-attainment
demonstration. T^at is, State decisions on control requirements
for solid waste incinerators are likely to be necessary in 1994
due to both section 129 and the attainment demonstration.
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19
D-3
Fuel Switching to Meet the Reasonably Available Control
Technology Requirements for Nitrogen Oxides
(July 30, 1993)
Under the Clean Air Act, States are required to adopt rules
to control emissions from major stationary sources of NOx.
Typically, those controls have involved modifications to
combustion equipment, such as installation of low NOx burners.
The new EPA policy allows States to adopt rules that permit
utilities to control NOx emission by switching to cleaner fuels
during the summertime ozone season. It stipulates that the NOx
emission reductions must be equal to or greater than emission
reductions that would have occurred had there been no switch to
the cleaner fuel.
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Fuel Switching
to Meet the
Reasonably Available Control Technology
Requirements for Nitrogen Oxides
July 30, 1993
Ozone/Carbon Monoxide Programs Branch
Air Quality Management Division
Office of Air Quality Planning and Standards
Environmental Protection Agency
Research Triangle Park, North Carolina
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Thursday, August 5.1993
This week EPA announces a new policy that will allow electric power utilities to switch t:
natural gas in the summertime to me^t requirements for reducing emissions of nitrogen oxide
(NOx). NOx combines with emissions of volatile organic compounds (VOCs) In the presence of
heat ana sunlight to form ground-level ozone, or smog. NOx is also a prime ingredient in the
formation of acid rain.
Under the Clean Air Act. States are required to adopt rules to control emissions from
major stationary sources of NOx Typically, those controls h*ve involve me aliens tc
combustion equipment, such as installation of low KOx burners.
Tne new EPA policy allots States to adopt rules that permit utilities to control NOx
emiss - by switching to clesi?r *uels during the summertime czone season, it stipulates that
the NC n ision reductions must be equal to or greater than emission reductions that would
have occurred had there been no switch to natural rsr,. »n many cases, this fuel switching wit! he
a much more cost-effective way of controlling NOx usslons than traditional "add-on" controls.
Besides providing more cost-effective options for rec jcing smog, the policy also offers
substantial pollution prevention p.nd global warmtno benefits * is not clear how many utilities
will switch to natural gas during the summer mortis. If, however, a large 600 megawatt
coal-fired utility boiler switched ir. natural gas for seven months of the year, It wculd reduce,
carbon dioxide emissions by an *stimated one million tons per year, emissions of sulfur diortde
by an estimated 20,000 tons per year, and emissions of paniculate matter by 40 tons per year. It
would also reduce mercury and other air toxics emissions.
The policy was announce in a July 30,1993, memorandum from Acting Assistant
Administrator for Air and Rao £. on Michael H. Shapiro 10 EPA regional office air programs.
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July 30, 1393
MFMORANr'JM
SUBJECT: Fuel .^..itching to Meet the Reasc.-'ably Available Control
Tecnr.jlogy (RACT) Requirements for Nitrogen Oxides
(NOx)
FROM: Michael H. Shapiro
Acting Assistant Administrator
for Air and Radiation (ANR-4^3)
": Director, Air, Pesticides and Toxics
Ma--a Cement Division, Regions 1 and IV
Director, Air and Waste Management Division,
': - -:ion II
Dir^-tcr, Air, Radiation and Toxics Division,
Region III
Director, Air c;nd Radiation Division,
Region V
Director, Air, Pesticides and Tcxics Division,
Region VI
Director, Air and Toxics Division,
Fegions VII, VIII, IX, and X
Purpose
The purpose of this memorandum is to provide guidance to
f-tates on the use of fuel switching tc meet the NOx RACT
requirements. As- described below, States can meet the NOx RACT
requirements by adopting rules which use a long-term emissions
eragirr. approach in a nanner consistent with the Environmental
; otect:e-i Agency's (EPA's) interim gund_ - -e for economic
incentive programs (ElP'b). The ZIP guic.--.cie vas published in
*che Federal Register (58 FR 11110, February 23, 1993).
"7. Background
Title I of the Clean Air Act (Act) Amendments of 1990
contains new requirements for areas that have not attained the
rational ambient air quality standards (N^ 3). These new
requirements include application of RACT c_ existing major
stationary sources of NOx in certain areas viat have not attained
trie ozone NAAQS a~d in the ozone transport region. The EPA
c .idance on these requirements is contained in 57 FR 55620,
November 25, 1992.
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The EPA guidance identifies presumptive RACT for certain
types of electric utility boilers in pounds of NOx per million
British thermal units (Btu) on a 30-day rolling average:
1. 0.45 for tangentially-fired coal burning.
2. 0.50 for dry bottom, wall-fired (other than cell burner)
coal burning.
3. 0.20 for tangentially-fired gas/oil burning.
4. 0.30 for wall-fired gas/oil burning.
For other source categories, the EPA guidance states that NOx
RACT may be set at levels that are comparable to the above levels
for certain utility boilers.
The EIP guidance is intended to stimulate the adoption of
incentive-based, innovative programs that will assist States in
meeting air quality goals through flexible approaches which allow
for less costly control strategies and which provide stronger
incentives for the development and implementation of innovative
emissions reductions technology. As described in that guidance,
long-term emissions averaging programs can be used by States to
meet the Act's RACT requirements. Key provisions of the EIP
guidance, with respect to the use of fuel switching to meet the
NOx RACT requirements, are described below.
Ill. Definitions
A. Fuel Switching
As used in this guidance, fuel switching refers to instances
where a unit historically burned one primary fuel, such as coal,
and under a "fuel switching" program the unit would burn a
cleaner fuel, such as natural gas, during the ozone season and
may switch back to the "historic" fuel for some or all of the
non-ozone season.
B. Base Year Fuel
For purposes of this guidance, the historical fuel refers to
the fuel that a unit primarily used during calendar year (CY)
1990. The EPA believes that CY 1990 is appropriate since many
Act requirements (such as reasonable further progress) stem from
this date. States are required to develop a comprehensive 1990
inventory, and the CY 1990 inventory is likely to be the most
accurate information readily available. Further, since this
guidance utilizes an annual emissions equivalency (described
below), the historical fuel needs to be based on an annual
period.
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More precisely, the historical fuel is defined as the fuel
burned most, on a Btu-weighted basis, during CY 1990. Where CY
1991 or CY 1992 is demonstrated to be more representative of
historic actual operating conditions, those years may be used.
For example, where a unit burned 90 percent coal during 1990-
1992, that unit is considered subject to the presumptive NOx FACT
limits for coal-fired units; if the same unit used 60 percent gas
in later years, it would still be subject to the presumptive NOx
RACT limits for coal-fired units.
C. Ozone Season
For purposes of this guidance, the ozone season generally
means the period of time that ozone monitoring is required for en
area as defined in 40 CFR part 58, appendix D, section 2.5.
D. Presumptive NOx RACT
For purposes of this guidance, presumptive NOx RACT means
the more stringent of the requirements:
1. adopted by the State into the State implementation plan
(SIP) to meet the NOx RACT requirements, or
2. defined in EPA's guidance published in 57 FR 55620,
November 25, 1992.
IV. NOx RACT for Fuel Switchers
Limited data indicate that, in some cases, a switch to
natural gas from coal could result in emissions in the 0.10 to
0.40 (pounds of NOx per million Btu) range as compared to the EPA
presumptive NOx RACT emissions rates for gas/oil of 0.20 to 0.30
and for coal of 0.45 to 0.50. This is a relatively broad range
and is based on very little data. The EPA has determined that*
there is not enough data available to establish a presumptive NOx
RACT level for a fuel-switcher category.
As a result, units that switch, for example, from coal
(historic fuel) to gas could fall under either the presumptive
coal or gas/oil NOx RACT limits. However, if fuel-switcher units
were required to meet the presumptive gas RACT limits, those
units would face the costs of both fuel switching and add-on
controls, which would remove an important incentive for coal
units to switch to gas. In these cases, EPA believes that the
presumptive RACT limits for coal are appropriate for establishing
the program baseline in an EIP because it is consistent with the
EIP guidance, data are not available to set a fuel switcher
presumptive NOx RACT level, there are clear environmental
benefits (noted below) when units switch to clean fuels, and fuel
switching might only occur under a coal baseline.
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4
V. Fuel Switching to Meet NOx RACT Through Long-Terro Averaging
A. EIP Approach
State rules which allow fuel switching to meet the NOx RACT
requirements are approvable where the rules are consistent with
the EIP guidance for long-term averaging and the guidance in this
memorandum. This approach is applicable to utility boilers as
well as any other source subject to the NOx RACT requirements.
Any source which meets the NOx RACT requirements through a long-
term averaging EIP must also meet all other relevant Act
requirements.
B. Emissions Limitation Requirements
The State rules must include emissions limits on both an
annual and ozone season basis, as described below.
C. Annual Emissions Limit
The EIP guidance provides States with the flexibility to
meet new RACT requirements, such as the NOx RACT requirements,
through an EIP that yields reductions in emissions at least
equivalent to those which would result from unit-by-unit
compliance with the presumptive RACT limit for that source
category. Under a long-term emissions averaging EIP to meet NOx
RACT, annual emissions of NOx must be less than or equal to
annual emissions that would result from compliance with
presumptive NOx RACT. The specific calculation methodology for
determining annual equivalence is described in the enclosed
appendix to this guidance.
D* Ozone Season Emissions Limit
An EIP that uses long-term emissions averaging to meet the
RACT requirements must include long-term emissions requirements,
as described above, and other requirements to show that the EIP
is equivalent to the presumptive RACT on a short-term basis. For
purposes of NOx RACT, a short-term emissions limit, in
conjunction with an annual emissions limit, satisfies these EIP
requirements. The short-term emissions limit must be applicable
in the ozone season and at least as stringent as the presumptive
NOx RACT limit. The more stringent of the State-adopted or EPA
presumptive NOx RACT must be required during the ozone season.
As discussed in the long-term averaging section of the EIP
guidance, a 24-hour averaging time is generally used to construct
attainment demonstrations in ozone nonattainment plans.
Accordingly, EPA believes that daily emissions limits should be
considered in the development of the EIP short-term emissions
limit requirements.
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VI. EIP Cost/Environmental Considerations
In general, the EIP guidance indicates (58 FR 11121) that
savings in compliance costs can result from EIP's and that
consideration might be given to the sharing of that benefit
between the regulated sources and the environmental goals of the
Act. The EIP guidance also states (58 FR 11117) that new RACT
requirements must be based on an analysis that considers the
incentive mechanism upon which the EIP is based. The EPA's
assessment of these issues for fuel switching is summarized
below.
A. Fuel—Switching Cost Considerations
In general, a fuel-switching program would provide new
flexibility to States and industry in meeting certain Act
requirements, including the NOx RACT requirements. Fuel
switching is a viable option for units where natural gas is
readily available since the price of natural gas in the ozone
season may be competitive with other fuels. While still meeting
the Act requirements, industry could, in some cases, avoid much
of the initial capital and operating costs associated with
combustion modifications.
As described above, fuel switching is expected to reduce the
cost to industry of meeting the NOx RACT requirements in some
cases. In other cases, the cost of a fuel-switching program may
exceed the cost of compliance with a presumptive RACT technology
such as a low-NOx burner and overfire air. The costs of a fuel-
switching program to industry will vary greatly from unit to unit
due to the availability of gas, price of gas, extent of needed
modifications to the boiler, and monitoring requirements.
B. Fuel-Switching Environmental Considerations
The EPA has considered the relative environmental benefits
for fuel switching and presumptive NOx RACT. In terms of the
primary purpose of NOx RACT, that is reducing ozone effects in
areas of high concentrations, it is clear that the increased NOx
emissions reductions due to burning a cleaner fuel during the
ozone season would be much more effective than lesser emissions
reductions at the presumptive NOx RACT levels, which would be
evenly spread over an entire year. The use of natural gas
instead of coal could also substantially reduce annual and
summertime emissions of sulfur dioxide (SO2), carbon dioxide
(C02), PM-10 (particles with an aerodynamic diameter less than or
equal to a nominal 10 micrometers), and associated toxic
emissions such as mercury. Further, emissions reductions of
these pollutants may be especially effective in the summer with
respect to reducing regional haze and sulfate-related PM-10, both
of which tend to peak in the summer. Thus, the potential
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benefits that go beyond the title I ozone and NOx RACT goals
include helping attain/maintain the NAAQS for SO2 and PM-10,
reducing mercury and other air toxic emissions, improving
visibility, and cutting emissions of CO2, a global warming gas.
The EPA has also considered evidence suggesting that, for
certain ecosystems, reductions in nitrogen deposition that occur
only during the summer would be less effective at reducing acid
deposition and nutrient impacts than reductions that occur
uniformly throughout the year. It is not possible at this time
to fully determine or quantify this relative ecological impact.
Moreover, due to the inherent limits on the amount of fuel
switching that can occur and the effect of titles II and IV NOx
reductions, wintertime nitrogen deposition would be projected to
decrease in most areas regardless of fuel switching. In
contrast, the ozone related and many of the additional potential
benefits of fuel switching noted above are well known and
quantifiable. In EPA's judgment, substantial additional ozone
reductions occur from fuel switching; this benefit and the
accompanying improvements in visibility, PM-10, air toxics, and
global warming that also occur from fuel switching clearly
outweigh the reduced wintertime benefits.
C. Conclusion
The above environmental and cost considerations are
important in interpreting the EIP guidance for the use of fuel
switching to meet NOx RACT. Based on these considerations, EPA
believes that, in cases where fuel switching results in a lower
cost to the source, requiring further environmental benefits
would not be necessary for fuel switching. Moreover, the
potential cost savings may need to be preserved to provide some
incentive to sources to achieve these substantial environmental
benefits.
VII. Enforcement
Each affected source in a long-term averaging program must
comply with all requirements imposed by the program. Each long-
term averaging program must:
1. Specify credible, workable, replicable and otherwise
fully enforceable methodologies for appropriately determining
compliance at all emissions units participating in the averaging
program, including methodologies for quantifying emissions, where
appropriate.
2. Require recordkeeping and reporting, consistent with the
required compliance determination methodologies, including
emissions quantification methodologies sufficient for determining
and documenting compliance with the program. These requirements
must contain a mechanism for determining required data, including
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emissions at subject emissions units when data are missing,
inadequate, or erroneous. This mechanism must ensure that owners
of emissions units have a strong incentive to properly perform
monitoring, recordkeeping, and reporting in the first instance.
3. Provide adequate civil and criminal sanctions for
failure to comply with applicable program requirements, including
emissions limitations and monitoring, recordkeeping, and
reporting requirements. The program regulatory requirements and
enforcement authorities must preserve the level of deterrence to
noncompliance, at both the State and Federal levels, which would
have otherwise applied in the absence of the averaging program.
VIII. Projected Results and Audit Procedures
A SIP revision that contains an EIP must include projections
of the emissions reductions the State expects to achieve through
implementation of the program. All EIP submittals must include
documentation which clearly states how sources in an EIP are or
will be addressed in the emissions inventory, reasonable further
progress (RFP) plan (i.e., where the 3 percent RFP plan includes
NOx substitution for required volatile organic compounds
reductions) and attainment or maintenance plan, as applicable.
All EIP's must also contain program audit procedures
designed to evaluate program implementation and track program
results in terms of the actual emissions reductions obtained
during program implementation. The program audit provisions must
include a State commitment to ensure timely implementation of
programmatic revisions or other measures which the State, in
response to the audit, deems necessary for the successful
operation of the program.
IX. Emissions Reduction Credits (ERC)
Annual emissions reductions achieved through the EIP that
exceed the annual emissions reductions that would result from
compliance with presumptive RACT may be used to establish ERC.
However, this guidance does not address establishing or trading
of seasonal ERC.
OAQPS:AQMD:OCPMB:DGRANO:MBINGHAM:13392:7/29/93
FILE:FUELSWJY.BA2: DISK:DGRANO.JK
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i = 100% coal
j = wall-fired utility boiler
assume presumptive coal RACT =0.5 (pounds NOx/MMBtu)
if historic (CY-90) production rates - 3 X 10s MMBtu/year
then the emissions cap is:
(3 X 10*) X (0.5) = 1.5 million pounds or 750 tons NOx/year
Annual emissions must, therefore, not exceed 750 tons for all
future years.
c. Multiple Fuel Emissions Averaging Example
£i-i-N2j-i-MRACT1:J X Annual Heat Input1:) >
Total Annual Actual NOX Emissions
i = 75% coal; 25% oil
j = wall-fired utility boiler
assume presumptive coal RACT =0.5 (pounds NOx/MMBtu)
assume the State has determined that the low NOx burner
technology designed for coal will result in a 0.35 emissions
rate when burning oil
if 1996 actual annual heat input (coal) = 3 X 106 MMBtu and
1996 actual annual heat input (oil) = 1 X 10* MMBtu
then actual 1996 annual emissions could not exceed:
(0.5) X (3 X 10s) =1.5 million pounds plus
(0.35) X (1 X 106) = 0.35 million pounds
which = 1.85 million pounds or 925 tons NOx
d. Multiple Fuel Emissions Cap Example
Emissions Cap = S^^S-j.^Historical Production Rate1:) X RACT1:)
i = 66.6% coal; 33.3% oil
j = wall-fired utility boiler
assume presumptive coal RACT =0.5 (pounds NOx/MMBtu)
assume the State has determined that the low NOx burner
technology designed for coal will result in a 0.35 emissions
rate when burning oil
if historic (CY 1990) production rates for coal = 2 X 106
MMBtu/year and
historic (CY 1990) production rates for oil = 1 X 106 MMBtu/year,
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then the emissions cap is:
(2 X 106) X (0.5) = 1 million pounds plus
(1 X 10s) X (0.35) = 0.35 million pounds
which =1.35 million pounds or 675 tons NOx
Annual emissions must, therefore, not exceed 675 tons for all
future years.
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Appendix; Annual Equivalency Calculation Methodology
A. Emissions Averaging or Emissions Cap
As described below, a long-term averaging EIP may use either
an emissions averaging or emissions cap basis to establish annual
equivalency. Under emissions averaging, if production increases,
emissions may increase proportionately; and if production
decreases, emissions must decrease accordingly. Shutdowns and
curtailments do not provide credit under an emissions averaging
program. Where an emissions cap is set, actual emissions must be
within the emissions cap for all appropriate averaging periods in
the future. Shutdowns and curtailments may provide credit under
an emissions cap under circumstances that will be described in
future guidance.
Both of these options assume that the State has determined a
RACT emissions rate value for each fuel i (up to N fuels) burned
in equipment j (for M types of equipment). The constraints in
this guidance presume that RACT is designated as an emissions
rate per unit of production (in this case heat input). The RACT
may also be designated as a percent reduction from representative
historical emissions rates.1 If a source wishes to implement a
long-term average percent reduction, the values must be converted
to emissions rate limits per unit of production.
Note, where multiple fuels are used in the base year, EPA
generally expects the presumptive RACT to be applicable to the
one primary fuel, and that different emissions rate limits would
be used for other fuels. For example, where coal has been
historically used 80 percent and oil 20 percent of the time in a
wall-fired boiler, the EPA presumptive RACT emissions limit of
0.5 (pounds of NOx per million Btu) might be used in the coal-
fired portion of the calculation; however, the EPA presumptive
RACT of 0.30 for oil might not be appropriate for the oil-fired
portion of the calculation since the presumed low NOx burner
technology designed to meet 0.5 when burning coal might not be
designed to meet 0.3 when burning oil. In this example, 0.35
might be more appropriate to include in the oil-fired portion of
the calculation; the State needs to determine the appropriate
emissions rate for the secondary fuel(s), considering the control
equipment designed to meet the primary fuel limit.
1 Generally speaking, the term "historical" means calendar
year 1990 unless another 12-month period is more representative
of normal source operation. This alternative 12-month period
must fall between January 1990 and December 1992.
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B. Emissions Averaging
Emissions averaging allows an emissions unit to use a
production-weighted average to meet the prescribed emissions rate
limitation (in this case the presumptive RACT limit) on an annual
basis. Actual annual emissions in each future compliance period
(mass per year) must be less than the emissions that would have
occurred if the presumptive RACT limit was met.
If RACT is designated as an emissions rate limitation, then
mathematically the constraint that must be met for every annual
compliance period in the future is as follows:
2i-i-N2j=1..HRACT1:, X Annual Heat Inputi:) >
Total Annual Actual NOX Emissions
Where RACT1:) generally eguals the lowest federally enforceable
emissions rate limitation that applies to unit j using fuel i.
There are limited exceptions to this generalization where an
emissions rate lower than RACTi3 would apply (e.g., see the
baseline section of the EIP guidelines). Further guidance is
expected to be released on this soon.
C. Emissions Cap
An emissions cap is an averaging approach that imposes a
limit on annual mass emissions from an emissions unit. The cap
is set using historical production rates and RACT emissions rate
limitations as shown below:
Emissions Cap = Si.j^j.^Historical Production Ratei;) X RACT1:)
Where RACT1;) is defined the same as above.
D. Example Determinations of Annual Equivalency
a. Single Fuel Emissions Averaging Example
x Annual Heat Input13 >
Total Annual Actual NOX Emissions
i - 100% coal
j = wall-fired utility boiler
assume presumptive coal RACT = 0.5 (pounds NOx/MMBtu)
if 1996 actual annual heat input = 4 X 106 MMBtu
then actual 1996 annual emissions could not exceed:
(0.5) X (4 X 106) = 2 million pounds or 1QQO tons NOx
b. Single Fuel Emissions Cap Example
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33
D-4
SIP Requirements for Areas Submitting Requests for
Redesignation to Attainment of Ozone and CO
NAAQS on or after November 15, 1992
(September 17, 1993)
This memorandum addresses State requests to redesignate from
nonattainment to attainment of the ozone and CO NAAQS under
section 107. It also allows NOx RACT exemptions for areas
redesignating to attainment.
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September 17, 1993
MEMORANDUM
SUBJECT: State Implementation Plan (SIP) Requirements for Areas
Submitting Requests for Redesignation to Attainment of
the Ozone and Carbon Monoxide (CO) National Ambient Air
Quality Standards (NAAQS) on or after November 15, 1992
FROM: Michael H. Shapiro
Acting Assistant Administrator
for Air and Radiation (ANR-443)
TO: Director, Air, Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
I. Purpose
The purpose of this memorandum is to address State requests
to redesignate from nonattainment to attainment of the ozone and
CO NAAQS under section 107. Specifically at issue are requests
submitted on or after November 15, 1992 where outstanding Clean
Air Act (Act) requirements have not been met. This memo provides
guidance on the statutorily-mandated control programs that must
be in the EPA-approved SIP if EPA is to approve the redesignation
request. The Act's requirements for redesignation and a list of
EPA's redesignation policy and guidance are included in
Attachments A and B. In the future, further guidance may be
provided for redesignations submitted after November 15, 1993.
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II. Policy Summary
Section 107(d)(3)(E)(v) of the Act as amended (amended Act)
provides that the State must have met all applicable requirements
of section 110 and part D in order to be redesignated.
Furthermore, section 107(d)(3)(E)(ii) provides that the State
must have a fully-approved SIP for the area seeking
redesignation.
The EPA is interpreting these section 107 provisions to
require satisfactory completion of the current Act planning
requirements. Specifically, before EPA can act favorably upon
any State redesignation request, the statutorily-mandated control
programs of section 110 and part D (that were due prior to the
time of the redesignation request) must have been adopted by the
State and approved by EPA into the SIP.
Thus, with respect to redesignation requests submitted on or
after the Act's deadline for submittal of the required programs,
States must generally adopt and provide for implementation of
their regulations for all of the programs that were due. States
must submit these plans to EPA for incorporation into the SIP.1
This would include such requirements as emissions inventories
and/or emission statements. Such requirements must be met in
order for the area to have a fully-approved SIP that meets all
requirements applicable to the area under section 110 and part D.
The amended Act, however, also provides that upon
redesignation, a State may move measures from the implemented SIP
to the contingency plan portion of the SIP if the State
demonstrates that such measures are not needed for maintaining
the NAAQS. Many areas sought redesignation at or about the same
time they were required to adopt and implement the requirements
due on November 15, 1992. In many instances, the State will be
able to immediately move these measures to the contingency plan
without implementation.
III. Exceptions to Policy
The EPA decided to review the requirements to determine if
something less than full adoption of these regulations would be
acceptable under the Act for areas seeking redesignation.
Exceptions to this policy on the States' need to complete the
full planning and adoption process for the November 15, 1992
mandated programs are very limited. The language in the Act
allows a degree of flexibility in only four program areas. These
are: (l) basic inspection and maintenance (I/M), (2) annual
'Note that this represents a departure from earlier guidance
for part D new source review (NSR) regulations.
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updates of vehicle miles traveled (VMT) forecasts and annual
estimates of actual VMT for CO nonattainment areas, (3) nitrogen
oxides (NOx) reasonably available control technology (RACT), and
(4) small business programs (SBP).
These exceptions are only applicable in areas for which EPA
approves a redesignation. The States should be aware that if EPA
denies a redesignation request, rules submitted in accordance
with this guidance may also be disapprovable. Finally, because
EPA anticipates issuing onboard regulations by January 1994,
States seeking redesignation of areas classified as moderate may
have some flexibility with respect to the Stage II requirement.
Our guidance for State submittals covering these four
programs is described in the following paragraphs.
Basic I/M
For areas where maintenance plans do not rely on
implementation of a basic I/M program immediately following
redesignation, the I/M component of the SIP should include:
1. Legislative authority for basic I/M such that
implementing regulations can be adopted without any further
legislative action.
2. A provision in the SIP providing that basic I/M be
placed in the contingency measures portion of the maintenance
plan upon redesignation.
3. An enforceable schedule and commitment by the Governor
or his designee for adoption and implementation of a basic I/M
program upon a specified, appropriate triggering event.
Note that, for purposes of consideration of a redesignation
request submitted after November 15, 1992, the commitment as
described in the I/M regulation (see 57 FR 52950, November 5,
1992) is not sufficient to meet the Act's requirement for a
fully-approved SIP.
In addition, please note that, EPA's final I/M regulations
in 40 CFR part 51 require a fully-adopted I/M program by
November 15, 1993. At this time, our preliminary interpretative
guidance on basic I/M in this memo is not discussed in the I/M
regulations. Therefore, EPA is proceeding to establish this
interpretation through regulatory action, thus enabling EPA to
accept legislative authority and a commitment to adopt and
implement basic I/M regulations for those areas being
redesignated to attainment.
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VMT Forecasting
The VMT forecasting SIP for CO should include:
1. Annual forecasts of VMT (i.e., average daily VMT for the
peak 3-month CO seasons for 1993, 1994, and 1995 in moderate
areas above 12.7 ppro, and until 2000 in serious areas).
2. An enforceable commitment by the Governor or his
designee to estimate actual annual VMT for each of these years
(by September 30 of the following year) and to update the
forecast of the VMT in the remaining years.
3. A request that the commitment be moved to the
contingency plan portion of the SIP upon redesignation, becoming
a contingency provision triggered by a specified triggering
event.
4. Adopted contingency measures to reduce CO emissions.
The implementation of such measures is contingent upon either:
(a) an annual estimate of actual VMT or updated forecast of VMT
exceeding the previous forecast for that year, or (b) the area
failing to attain by the CO attainment deadline. These
contingency measures must meet the requirements of section
I87(a)(3) as interpreted by the April 16, 1992, "General Preamble
for the Implementation of Title I of the Clean Air Act Amendments
of 1990," including the requirement that no further action by the
State is needed for them to take effect.
NOx RACT
Section 182(f) provides that States may request an exemption
from the NOx RACT requirements. The NOx RACT requirements of
section 182(f) do not apply if additional reductions of NOx would
not contribute to attainment.2 In an area that did not implement
the section 182(f) NOx requirement but did meet the ozone
standard, as demonstrated by adequate monitoring data consistent
with EPA guidance, it is clear that the additional NOx reductions
required by section 182(f) would not contribute to attainment,
although they might contribute to maintenance. Therefore, EPA
believes that if a State submits a redesignation request along
with a section 182(f) exemption request based on monitoring data
demonstrating attainment of the ozone NAAQS, further
documentation is not required. The State may follow one of two
2Note that the section 182(f) exemption for NOx RACT and NSR
requirements described in this section is applicable only for
States outside an ozone transport region, since only those States
fall under the section 182(f) "contribute to attainment"
provision.
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approaches in making such a submittal:
1. Submit a redesignation request along with a section
182(f) exemption request based solely upon monitoring data
showing that the area's air quality is meeting the ozone NAAQS;
and submit a maintenance plan SIP revision, which includes a NOx
RACT program as a contingency measure. In lieu of adopted NOx
RACT rules, such a NOx RACT program may consist of an enforceable
schedule and commitment by the Governor or his designee to adopt
and implement the NOx RACT rules upon a specified, appropriate
triggering event.
2. An exemption request based on both ambient monitoring
and urban airshed modeling consistent with EPA guidance that
shows additional NOx reductions would not contribute to
attainment in the area. In this case, NOx RACT rules do not have
to be included as a contingency measure of the maintenance plan.
For several reasons, the Act can be interpreted as not
requiring the section 507 SBP submittal in order for EPA to
approve a redesignation request. The SBP submittal is required
regardless of whether there are any designated nonattainment
areas within the State. In addition, the SBP is not a control
measure intended to contribute to the emission reductions
achieved by an area; rather it is a service provided to help
small businesses comply with requirements of the Act. For the
above reasons, EPA is interpreting the SBP as not being an
applicable requirement for any specific nonattainment area that
is seeking redesignation. However, EPA will continue to ensure
that States make SBP submittals in a timely fashion.
Stage II Vapor Recovery
Stage II vapor recovery remains an applicable requirement
for moderate ozone nonattainment areas until EPA promulgates
onboard vapor recovery regulations. Section 202(a)(6) of the Act
provides that once onboard regulations are promulgated, the Stage
II regulations required under section 182(b)(3) are no longer
applicable for moderate ozone nonattainment areas. Therefore,
final redesignation for a moderate nonattainment area that occurs
after EPA's onboard regulations are promulgated does not have to
include a Stage II SIP control program. For redesignation
requests that are submitted before EPA promulgates onboard rules
and that do not include Stage II rules for moderate areas,
Regional Offices may prepare rulemaking actions proposing to
approve the redesignation, if appropriate, as long as final
approval occurs after EPA promulgates onboard regulations.
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IV. Coordination of SIP Submittals and Redesiccnation
Requests
If the State elects to follow the approach above, the State
should submit the SIP control program as described above along
with the redesignation request and maintenance plan. The EPA
will review the required SIP submittal(s) against EPA policy and
guidance and in coordination with the redesignation request and
maintenance plan. Approvability of the redesignation is directly
related to the approvability of the SIP submittals (i.e., EPA is
precluded from approving a redesignation to attainment if the SIP
is not approvable).
As a general policy, a State may not relax the adopted and
implemented SIP for an area upon the area's redesignation to
attainment. States should continue to implement existing control
strategies in order to maintain the standard. However, section
175A recognizes that States may be able to move SIP measures to
the contingency plan upon redesignation if the State can
adequately demonstrate that such action will not interfere with
maintenance of the standard. The type of demonstration necessary
is dependent upon the pollutant for which the area has been
redesignated to attainment.
In order to make such a demonstration for an area
redesignated to attainment for CO, EPA believes that the State
could submit a revised control strategy demonstration showing
that the measure is not necessary to maintain the standard. For
ozone, the State would need to submit an attainment modeling
demonstration consistent with EPA's current "Guideline on Air
Quality Models," showing that the control measure is not needed
to maintain the standard. The EPA intends to be very cautious in
approving such revisions in cases where the control measures were
implemented during the time the area attained the standard; the
State's demonstration should indicate an ample margin of safety
with respect to maintenance of the standard.
V. Conclusion
In summary, full adoption of all of the statutorily-required
programs, as well as a schedule and an enforceable commitment for
an implementation date, are necessary for redesignation to
attainment from nonattainment for ozone or CO if the
redesignation request is submitted after the statutory due date
for the program. The few exceptions to this requirement are
basic I/M, annual updates of VMT forecasts, and estimates of
actual VMT, NOx RACT, and SEP.
If you have any questions, please contact Sharon Reinders at
(919) 541-5284, or Annie Nikbakht at (919) 541-5246.
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Attachments
cc: Air Branch Chief, Regions I-X
Kent Berry, AQMD
Rob Brenner, OAR
Mary Henigin, OAQPS
Alan Eckert, OGC
Robert Kellam, TSD
Rich Ossias, OGC
John Seitz, OAQPS
Paul Stolpman, OAR
Jan Tierney, OGC
Lydia Wegman, OAQPS
Dick Wilson, OMS
bcc: Valerie Broadwell, AQMD
John Cabaniss, OMS
David Cole, AQMD
Denise Gerth, AQMD
Tom Helms, AQMD
Ed Li11is, AQMD
Phil Lorang, OMS
David Misenheimer, TSD
David Mobley, TSD
Annie Nikbakht, AQMD
Carla Oldham, AQMD
Sharon Reinders, AQMD
John Silvasi, AQMD
David Soloman, AQMD
Gene Tierney, OMS
Regional Contacts
This memorandum has been under development for several months.
It has been coordinated with OGC (Jan Tierney, Rich Ossias), OMS
(John Chamberlin, Al Mannato), Regional Air Division Directors
and Air Branch Chiefs, NSR (Mike Sewell, David Solomon), and TSD
(David Misenheimer).
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Attachment A
Criteria For Redesignation Under Section 107(d)
Section 107(d)(3)(E) of the Act states five criteria that
roust be met before the Administrator may redesignate an area to
attainment. The criteria are:
1. The EPA has determined that the NAAQS have been
attained.
2. The applicable implementation plan has been fully
approved by EPA under section 110(k).
3. The EPA has determined that the improvement in air
quality is due to permanent and enforceable reductions in
emissions.
4. The State has met all applicable requirements for the
area under section 110 and part D.
5. The EPA has fully approved a maintenance plan, including
a contingency plan, for the area under section 175A.
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Attachment B
The EPA policies for implementing section 107 of the Act for
redesignations are contained in the following memorandums.
1. "Procedures for Processing Requests to Redesignate Areas
to Attainment," John Calcagni, Director, Air Quality Management
Division, September 4, 1992.
2. "State Implementation Plan (SIP) Actions Submitted in
Response to Clean Air Act (CAA) Deadlines," John Calcagni,
Director, Air Quality Management Division, October 28, 1992.
3. "Contingency Measures for Ozone and Carbon Monoxide (CO)
Redesignations," G. T. Helms, Chief, Ozone/Carbon Monoxide
Programs Branch, June 1, 1992.
4. "Maintenance Plans for Redesignation of Ozone and Carbon
Monoxide Nonattainment Areas," G. T. Helms, Chief, Ozone/Carbon
Monoxide Programs Branch, April 30, 1992.
In the event that EPA does not approve the redesignation,
the applicable I/M program requirements and guidance can be found
in 57 FR 52950, November 5, 1992 and in 40 CFR part 51. The
applicable VMT forecast guidance is described in the document
entitled, "Section 187 VMT Forecasting and Tracking Guidance,"
January 1992.
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43
D-5
NOx Substitution Guidance
(December, 1993)
Title I of the Clean Air Act (Act) mandates a 15% reduction
of volatile organic compound (VOC) emissions from the 1990 base
inventory by November, 1996 in all ozone nonattainment areas
classified moderate and above. Areas classified serious and
above must achieve the 3 % per year VOC reductions past November,
1996 as part of the reasonable further progress (RFP) provision
in the Act. However, the Act allows the post-1996 RFP plan to
accommodate a less than 3 % per year VOC reduction if it can be
demonstrated that substitution of NOx emission reductions (for
VOC reductions) yields equivalent ozone reductions.
This guidance is designed to introduce greater flexibility
in developing ozone attainment strategies by utilizing NOx
emission reductions for meeting RFP requirements after 1996.
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NOx SUBSTITUTION GUIDANCE
December, 1993
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
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Section l: Background
Title I of the Clean Air Act Amendments (CAAA) mandates a
15% reduction of volatile organic compound (VOC) emissions from
the 1990 base inventory by November, 1996 in all ozone
nonattainment areas classified moderate and above. Areas
classified serious and above must achieve the 3% per year VOC
reductions past November, 1996 as part of the reasonable further
progress (RFP) provisions (§ 182 [c][2][B]). However, Section
182 (c)(2)(C) allows the post-1996 RFP plan to accommodate a less
than 3% per year VOC reduction if it can be demonstrated that
substitution of NOx emission reductions (for VOC reductions)
yields equivalent ozone reductions. Underlying this substitution
provision is the recognition that NOx controls may effectively
reduce ozone in many areas, and that the design of strategies is
more efficient when the characteristic properties responsible for
ozone formation and control are evaluated for each area.
The purpose of this document is to provide a. procedure that
can be applied to meet the post-1996 Section 182(c)(2)(B) RFP
requirement as well as the Section 182 (c)(2)(C) equivalency
demonstration requirements. The intent of this guidance is to
facilitate implementation of the most effective ozone precursor
control strategies, while meeting the intent of the CAA RFP
provisions.
The guidance consists of two basic steps that are
established in Sections 2 and 3 of this document. First, an
equivalency demonstration requires that cumulative RFP emission
reductions must be consistent with the NOx and VOC emission
reductions determined in the ozone attainment modeling
demonstration. Second, specified reductions in NOx and VOC
emissions should be accomplished in the interim period between
1996 and the attainment date, consistent with the continuous RFP
emission reduction requirement. Section 4 provides the legal
rationale underlying this guidance and the guidance is summarized
in Section 5.
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Section 2: Test for Equivalency - Use of Strategies Aimed at
the Mandated Attainment Year
[The condition for demonstrating equivalency is that State-
proposed emission control strategies must be consistent with
emission reductions required to demonstrate attainment of
the ozone NAAQS for the designated year of attainment.]
The provision for NOx substitution recognizes that a VOC-
only control pathway may not be the most effective approach for
effecting attainment in all areas. Consequently, NOx reductions
are placed on a near equal footing with VOC through substitution.
This document establishes two conditions pursuant to both the
substitution and RFP provisions in the Act. The first condition
requires that control strategies incorporating NOx emission
reduction measures must demonstrate that the ozone NAAQS will be
attained within time periods mandated by the Act. This condition
reflects the Title I provision for gridded photochemical model
demonstrations (Section 182(c)).
The second condition, addressed below in Section 3,
maintains the requirement for periodic emission reductions in
order to realize progress toward attainment. Flexibility is
introduced by allowing VOC and NOx reductions rather than VOC
reductions alone. A third condition exists in which the periodic
emission reductions must be consistent with the model attainment
demonstration.
The basis for equivalency is the ability of a given control
strategy (i.e., any particular mix of NOx and VOC emission
reductions) to effect attainment of the ozone NAAQS by the
designated attainment year. Section 182(c) of the CAA requires
that State implementation plans (SIPs) for serious and above
nonattainment areas include a demonstration of attainment of the
ozone National Ambient Air Quality Ambient Standard (NAAQS) with
gridded photochemical modeling. These SIP revisions are due by
November 15, 1994 and provide the framework for demonstrating
equivalent ozone reductions through the substitution of NOx
emission reductions for VOCs. Model application procedures for
demonstrating attainment are provided in EPA's Guideline for
Regulatory Application of the Urban Airshed Model. (EPA-450/4-91-
013) .
This modeling requirement already exists as a Title I
provision for areas classified serious and above. Due to the
flexibility described below in Section 3.0 which permits
virtually any set of NOx and VOC RFP reductions in years prior to
the attainment date, a linkage to the attainment year control
strategy is required. This linkage provides assurance that the
RFP reductions are consistent with the SIP attainment
demonstration. States are required to justify substitution by
illustrating "consistency" between the cumulative emission
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changes emerging from the RFP/substitution proposal and the
emission reductions in the model attainment demonstration (or
comparable modeling analysis). The EPA will approve substitution
proposals on a case-by-case basis. Generally speaking, any
reasonable substitution proposal will be approved. Linkage to
the modeling demonstration provides a screen to remove
unrealistic (and inefficient) substitution proposals.
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Section 3: Reasonable Further Progress (RFP) Requirements
[The condition for meeting the RFP emissions reduction
provision is that the sum of all creditable VOC and NOx
emission reductions must equal 3% per year averaged every
three years.]
The RFP provisions require periodic emissions reductions
until attainment is reached. In the absence of the NOx
substitution provision, an area classified serious or above would
be required to reduce VOC emissions after 1996 an average of 3%
per year every three year period until attainment. This guidance
maintains the 3% per year emissions reduction requirement.
However, no specified set of VOC or NOx controls is mandated.
Reasons for not requiring specific "exchange" rates among VOC and
NOx emissions include:
1. The strong likelihood that optimum "exchange" rates
vary from year to year and across a geographic area as
an area's emissions distribution and atmospheric
chemistry change over time;
2. Uncertainty in modeling analyses, particularly when
attempting to ascertain responses from small percentage
perturbations in emissions; and
3. Resource limitations associated with modeling specific
control measures during interim years before attainment
dates.
Any combination of VOC and NOx emission reductions which
totals 3% per year, and meet other SIP consistency requirements
described in this document are allowed. These requirements
ensure that the cumulative RFP reductions are consistent with the
emission reduction measures identified in the model attainment
demonstration. A percentage basis rather than a mass basis is
used for calculating the RFP emission reductions. A percentage
basis is applied to avoid "absurd" calculations. For example,
substitution of NOx reductions for VOC on a ton for ton basis
could yield calculated NOx reduction requirements which exceed
the available NOx inventory in cases where the base VOC inventory
greatly exceeds the NOx inventory. To illustrate, a 50% VOC
reduction is analogous to a 100% NOx reduction assuming the VOC
inventory is twice the NOx inventory and substitution is based on
mass rather than percentage equivalency. The percentage basis
also is consistent with the RFP "percent" reduction requirement,
therefore buoying the legal justification underlying this
guidance.
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The calculation to determine yearly VOC and NOx emission
reduction totals must be based on typical summer day inventories
(same basis used for RFP and modeling inventories). Specific
details regarding calculation procedures and emission inventory
definitions are found in separate documents, including EPA's
forthcoming Guidance on the Post-1996 Rate-of-Proaress Plan and
the Attainment Demonstration. The following equation generally
describes the method to calculate the total 3% per year emission
reductions:
RV/VOCBASE + RN/NOXBASE >= 0.03
where; Rv = typical summer day VOC reductions in mass units
RN = typical summer day NOx reductions in mass units
VOCBASE = the mass of anthropogenic VOC emissions
in the 1990 adjusted base inventory, and
NOxBASE = the mass of anthropogenic NOx emissions
in the 1990 adjusted base inventory
[note, the cumulative mass reductions are not
constrained to 3% per year so that RFP reductions
greater than 3% per year are not discouraged.]
The values of Rv and RN include only the creditable emission
reductions from the nonattainment area of concern.
For instance, VOC or NOx reductions from the pre-enactment
Federal Motor Vehicle Control Program (FMVCP), which are not
creditable toward the 3% per year requirement are not included.
Potential "creditable" NOx emission reductions which are
available for substitution purposes are described in EPA's
forthcoming Guidance on the Post-1996 Rate-of-Progress Plan and
the Attainment Demonstration.
The attainment strategy requirements must be met in addition
to the RFP condition. Total emission reductions are determined
by the attainment demonstration, implying that reductions
averaging greater than 3% per year averaged from 1996 to the
specified attainment year are required if shown to be necessary
by the model demonstration. The 3% per year RFP requirement is
thus a minimum requirement. Further, the NOx emission reductions
credited toward RFP may be capped by the cumulative reductions
dictated by the model demonstration. For example, an approved
control strategy emerging from a model demonstration for a
serious area might show reductions of 6% NOx and 80% VOC,
relative to 1990 emissions, are needed by 1999. Assuming zero
creditable NOx emission reductions from 1990 through 1996, NOx
reductions averaging 2% per year over the 3 years from 1996 to
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1999 represent a cap on the NOx RFP reductions. The reason for
linking the RFP reductions to the attainment strategy is to avoid
RFP reductions which are not consistent with the model
demonstration. Note that the sum of emissions totalling 3% per
year are required to meet the basic RFP provisions — they are
not capped by the attainment demonstration. Thus, cases might
exist where VOC reductions from the RFP provisions might exceed
the cumulative VOC emission reductions in the attainment
strategy. Such cases do not conflict with the attainment
demonstration since additional VOC reductions will not increase
peak ozone. On the other hand, the NOx cap is necessary because
NOx reductions have the potential for increasing peak ozone.
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Section 4: Discussion of Equivalency
[The following discussion provides the legal rationale
underlying the interpretation of "equivalency" and the
linkage between the RFP and NOx substitution provisions
within the Act.]
"Equivalency" is not defined strictly in the context of,
"What specified level of NOx reductions, compared to VOC, results
in equivalent ozone reduction?" Instead, any combination of VOC
and NOx reductions is "equivalent" so long as the reductions are
consistent with those identified as necessary to attain the NAACS
in the modeling demonstration and provide for steady progress in
leading to the emission reductions identified as necessary to
attain the NAAQS by the specified attainment year.
In allowing a combination of NOx and VOC controls or the
substitution of NOx emissions reductions for VOC emissions
reductions, Section 182(c)(2)(C) of the statute states that the
resulting reductions "in ozone concentrations" must be "at least
equivalent" to that which would result from the 3% VOC reductions
required as a demonstration of reasonable further progress (RF?)
under Section 182(c)(2)(B). This provision could be interpreted
to mean that the amount of NOx reductions appropriate for
substitution purposes is an amount which, when compared to
predicted VOC reductions, results in the same reductions in ozone
concentrations that the VOC reductions would achieve in that
area. However, such an interpretation could result in a
demonstration showing that very small NOx reductions provide an
adequate substitute for large VOC reductions. This is because
under some conditions substantial VOC reductions produce only
small - even insignificant - reductions in ozone concentrations,
while minimal NOx reductions under the same conditions may
produce the same degree of ozone reductions. EPA believes
Congress would not have intended States to meet the Act's
progress requirements with emissions reductions that would
produce only minimal improvement in ozone concentrations.
The second sentence of Section 182(c)(2)(C) requires EPA to
issue guidance "concerning the conditions under which NOx control
may be substituted for [or combined with] VOC control." In
particular, the Agency is authorized to address in the guidance
the appropriate amounts of VOC control and NOx control needed, in
combination, "in order to maximize the reduction in ozone air
pollution." Further, the Act explicitly provides that the
guidance may permit RFP demonstrations which allow a lower
percentage of VOC emission reductions. The implicit assumption
under that language is that such lesser levels of VOC reductions
would be allowed only because of the correspondingly higher
percentage of NOx emission reductions to be authorized as a full
or partial substitution for the otherwise required VOC
reductions. In light of the entire set of language and
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Congress's evident intent under this subsection to maximize the
opportunity for ozone reductions, EPA believes that Section
182(c)(2)(C) confers on the Agency the discretion to select, for
purposes of determining equivalent reductions, a percentage of
NOx emission reductions which is reasonably calculated to achieve
both the ozone reduction and attainment progress goals intended
by Congress. Nothing in the Act or in the legislative history
directly addresses the case where NOx reductions that are
substituted for VOC reductions, and which meet the plain
grammatical meaning of "equivalency," nonetheless result in
insignificant ozone reductions. To avoid such a result and give
meaningful effect to what Congress likely intended regarding the
substitution provision, EPA has decided to rely in its NOx
substitution guidance on the only point of reference provided by
Congress concerning what may constitute an appropriate
quantitative reduction target for RFP purposes, namely the 3
percent per year required under Section 182(c)(2)(B). Under that
approach, EPA would approve substitutions of NOx for VOC that
would ensure that the sum of the respective creditable percent
reductions of each of these pollutants areawide, averaged over 3
years, would be no less than 3 percent from the baseline.
As additional evidence that Congress was concerned with
getting more than minimal reductions in ozone concentrations
through substitution, EPA notes that the RFP demonstration
described in Section 182(c)(2)(B) focuses on reductions of a
specified quantity of VOC emissions per year. (Similarly, the 15
percent RFP reductions required for Moderate ozone nonattainment
areas focuses on reductions of that specific quantity of VOC
emissions per year.) By contrast, the alternative RFP
demonstration in Section 182(c)(2)(C) allows flexible VOC/NOx
emission reduction strategies, but only so long as the overall
quantitative reduction in ozone concentrations is equivalent to
the amount which, for Serious ozone nonattainment areas, Congress
initially determined must be met (i.e., the ozone concentrations
achieved by VOC reductions of 3 percent per year) in order to
ensure expeditious progress towards attainment. In this regard
the House Committee Report states: "NOx reductions may not be
substituted for VOC reductions in a manner that delays attainment
of the ozone standard or that results in lesser annual reductions
in ozone concentration than provided for in the attainment
demonstration." H.R. Resp NO. 490, 101st Cong., 2d Sess. 239
(1990).
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Section 5: Summary
The RFP requirements under Section 182(c)(2)(B) of the CAA
are intended to insure that the SIP "provide for such specific
annual reductions in emissions of VOC and NOx as necessary to
attain the NAAQS for ozone by the applicable attainment date."
This language is interpreted to mean that, to meet the RFP
requirement, it is necessary to show that steady progress is
being made toward implementing measures called for in an area's
attainment strategy. Further, the Act also specifies minimal
annual percentage reductions in creditable emissions which must
be realized in an RFP program. Section 182(c)(2)(C) increases
the flexibility in which the annual emission reductions can be
derived by allowing NOx emission reductions substitution for VOC
after 1996. The recommended procedure responds to these concerns
by imposing two requirements.
1. Establish a strategy incorporating reductions in VOC
and/or NOx sufficient to meet the NAAQS within
timeframes specified by the Act. This is to be done
using approved photochemical grid models in a manner
consistent with published Agency guidance on the use of
such models in attainment demonstrations. In the
context of the NOx substitution guidance, the purpose
of this first step is to establish an ultimate target
toward which the RFP program is aimed.
2. For interim years, any mix of annual reductions in VOC
and NOx is permissible so long as it reflects
(a) a logical step toward implementing the attainment
strategy identified in (1), and
(b) results in a combined annual VOC and NOx reduction
of 3% per year.
The requirement for continuous VOC emission reductions
amounting to 3% per year has been modified to allow flexibility
in the mix of VOC and NOx emission reductions, while maintaining
a 3% per year reduction in the sum of NOx and VOC emissions. A
principal assumption underlying this guidance is that optimum
control strategy designs may differ among various nonattainment
areas.
The NOx substitution provision permits greater flexibility
for States in designing effective emissions control strategies.
Furthermore, because the test for equivalency is identical to the
NAAQS attainment test for serious and above areas, the
demonstration imposes negligible additional resource burdens for
those areas already required to perform gridded photochemical
modeling.
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54
D-6
Guideline for Determining the Applicability of
NOx Requirements Under Section 182(f)
(December, 1993)
The Clean Air Act (Act) includes provisions in section
182(f) to control emissions of nitrogen oxides (NOx) in certain
ozone nonattainment areas and ozone transport regions. Section
182(f) also specifies circumstances under which the new NOx
requirements would be limited or would not apply. This document
describes EPA's views on how EPA should interpret section 182(f)
and the circumstances under which EPA would determine that the
new NOx requirements would be limited or would not apply.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Air Quality Planning and Standards * --•
Research Triangle Park, North Carolina 2771 1
16 DEC 1993
MEMORANDUM
SUBJECT:
FROM:
TO:
Guideline for Determining the Applicability of Nitrogen
Oxide Requirements under Section 182 (t)
John S. Seitz, Director
Office of Air Quality
(MD-10)
Director, Air, Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
I am attaching a copy of the subject policy document for
dissemination to State and local air pollution control agencies.
Section 182 (f) of the Clean Air Act (Act) contains the
requirement for application of reasonably available control
technology and new source review for major sources of nitrogen
oxides (NOx) in ozone nonattainment areas classified moderate or
above and in the Ozone Transport Region. Section 182 (f) also
contains provisions for exempting areas from these NOx
requirements. This guideline, although not specifically required
by the Act, indicates how the Environmental Protection Agency
expects to handle the exemption provisi.on.
Questions on this document should be referred to Doug Grano
(919-541-3292) or John Silvasi (919-541-5666) of this office.
Please distribute this document to the State and local agencies
in your Region.
Attachment
cc: NOx Work Group Members
Kent Berry
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GUIDELINE FOR DETERMINING THE APPLICABILITY
OF NITROGEN OXIDES REQUIREMENT UNDER
SECTION 1
DECEMBER 1993
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Air Quality Management Division
Research Triangle Park, NC 27711
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GUIDELINE FOR DETERMINING THE APPLICABILITY
OF NITROGEN OXIDES REQUIREMENTS UNDER SECTION 182m
CONTENTS
CHAPTERS
INTRODUCTION
1.1 General
1.2 Nitrogen Oxides Supplement to the General Preamble for
Implementation of Title I of the Clean Air Act
1.3 Section 185B Report
1.4 Application of Section 182(f) Requirements
ADMINISTRATIVE PROCEDURES
2.1 Processing with the State Implementation Plan (SIP)
Revision
2.2 Petition
NET AIR QUALITY BENEFIT
3.1 Demonstration
3.2 Factors
3.3 Geographic Scope
3.4 Scenarios
3.5 Sources
CONTRIBUTE TO ATTAINMENT
4.1 Demonstration
4.2 Episodes to Consider
4.3 Geographic Scope
4.4 Applicability to Areas Requesting Redesignation to
Attainment
NET OZONE AIR QUALITY BENEFIT
5.1 Demonstration
5.2 Factors
5.3 Attainment/Unclassified Portions
EXCESS EMISSIONS REDUCTIONS
6.1 General
6.2 Demonstration
MODELING TECHNIQUES
7.1 Photochemical Grid Modeling
7.2 Urban Airshed Model
7.3 Regional Scale Modeling
7.4 Model Results and SIP Interface
7.5 Other Analytical Techniques
EMISSIONS ANALYSIS
8.1 General
8.2 Biogenic Volatile Organic Compound (VOC) Emissions
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8.3 Years to Analyze
8.4 Scenarios to Compare
8.5 Consistency with the SIP
8.6 New Source Review
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CHAPTER 1
INTRODUCTION
1.1 General
The Clean Air Act (CAA), as amended in 1990, includes new
provisions in section 182(f) to control emissions of nitrogen
oxides (NOx) in certain ozone nonattainment areas and ozone
transport regions. Section 182(f) also specifies circumstances
under which the new NOx requirements would be limited or would
not apply. This document describes EPA's preliminary views on
how EPA should interpret section 182(f) and the circumstances
under which EPA would determine that the new NOx requirements
would be limited or would not apply.
Although this document includes various statements that
States or petitioners must take certain actions, these statements
are guidance made pursuant to EPA's preliminary interpretations,
and thus do not bind the States and the public as a matter of
law. The EPA's interpretation of the section 182(f) provisions
will provide a basis for subsequent EPA approval or disapproval
of requests for exemption from the new NOx requirements. While
this document contains guidance on the interpretation of the
section 182(f) provisions, unique circumstances or as yet
unrecognized issues are likely to cause case-by-case exceptions
to arise. The EPA intends to provide the public with an
opportunity to comment on any exemption requests received by the
Agency.
1.2 Nitrogen Oxides Supplement to the General Preamble for
Implementation of Title I of the Clean Air Act
The new NOx requirements, which are summarized below, are
described in detail in EPA's Nitrogen Oxides Supplement to the
General Preamble for Implementation of Title I of the Clean Air
Act. This guidance was published in the Federal Register on
November 25, 1992 (57 FR 55620).
Section 182(f) requires States to apply the same
requirements to major stationary sources of NOX as are applied to
major stationary sources of volatile organic compounds (VOC).
The new NOx requirements are reasonably available control
technology (RACT) and new source review (NSR). These
requirements apply to major stationary sources in certain areas
that are designated nonattainment for the ozone national ambient
air quality standard (NAAQS) and in an ozone transport region.
The RACT requirements are in section 182(b)(2). This
section requires RACT for major NOx stationary sources in ozone
nonattainanent areas classified moderate and above as well as in
an ozone transport region. States are required to submit
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regulations fcror RACT by November 15, 1992 and sources are
required fc.o achieve compliance with RACT by May 31, 1995. The
EPA has ckafinasd RACT as the lowest emission limitation that a
particular- sooirce is capable of meeting by the application of
control tescbnjDlogy that is reasonably available considering
technological .and economic feasibility (44 FR 53762; September
17, 1979)..
The KSR s-equirements are in section 182(a) (2) (C). This
section requires States to adopt revised NSR regulations in ozone
nonattainwent areas classified marginal and above as well as
within an ozonae transport region. States are required to submit
regulations far NSR by November 15, 1992. NSR provisions require
major new
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1.4 Application of Section 182flM Requirements
Section 182(f)(l) provides that the new NOx requirements
shall not apply if the Administrator determines that any one of
the following tests is met:
(1) in any area, the net air quality benefits are greater
in the abs<
concerned;
in the absence of NOX reductions from the sources
(2) in nonattainment areas not within an ozone transport
region, additional NOX reductions would not contribute
to ozone attainment in the area; or
(3) in nonattainment areas within an ozone transport
region, additional NOX reductions would not produce net
ozone air quality benefits in the transport region.
Further, section 182(f)(2) states that the application of
the new NOx requirements may be limited to the extent necessary
to avoid excess reductions of NOx as determined by applying tests
similar to tests (l)-(3) above.
As described in this document, the "net air quality
benefits" test and the "excess emissions" provision may be
applied in an ozone transport region or outside the transport
region; the "contribute to attainment" test may only be applied
outside of an ozone transport region; and the "net ozone
benefits" test may only be applied within an ozone transport
region. Where any one of the tests is met (even if another test
is failed), the section 182(f) NOx requirements would not apply
or, under the excess reductions provision, a portion of these
requirements would not apply.
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CHAPTER 2
ADMINISTRATIVE PROCEDURES
2.1 Processing with the State Implementation Plan fSIP) Revision
A State may, at any time, demonstrate to the Administrator
that the new NOx requirements should not apply. For example, a
State may submit a demonstration under section 182(f) along with,
or as a revision to, the SIP at the time the NOx RACT rules are
due; or a State may choose to submit the section 182(f)
demonstration at a later date along with or as part of a separate
SIP revision. The State's demonstration is not required to be a
SIP revision itself.
The EPA will approve or disapprove the State's demonstration
when the Administrator approves a plan or plan revision. The EPA
will consider the section 185B report and will base its decision
on the demonstration and supporting information provided by the
State. Such demonstration and information should be in
sufficient detail for EPA to determine that the exemption request
is consistent with the guidance contained in this section 182(f)
document. The EPA encourages the States to consult with the
appropriate EPA Regional Office during the development of the
documentation. This is necessary to ensure that the
documentation provided by the State is likely to be approved and
that any required rules can be adopted in a timely manner. NOx
RACT and/or NSR rules that have been submitted or were previously
approved by EPA would continue to be processed for approval or
continue to be enforced while EPA considered the section 182(f)
demonstration.
2.2 Petition
Section 182(f)(3) provides that a person (including a State)
may petition the Administrator for a NOX exemption at any time
after the final section 185B report is submitted to Congress.
The petition may be made with respect to any nonattainment area
or any ozone transport region. The EPA must grant or deny a
petition within 6 months after its filing.
Since an individual petition is likely to affect the SIP
planning process which is primarily a State responsibility, EPA
believes it is reasonable to require the petitioner to provide a
copy of the petition and demonstration to the State or States
which have jurisdiction over the source or sources covered by the
petition at the same time it is submitted to the Administrator
(where a petition under section 182(f)(3) is being submitted by a
person other than the State itself). Where additional States may
be affected by the petition, the State receiving the petition
should coordinate with the other States as necessary. In some
cases there may be multiple petitions for a given area. In other
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cases a single petition may have multi-State implications.
Shortly after EPA receives a petition, the Agency will announce
its receipt and availability for public review in the Federal
Register. The EPA will provide the State(s) a 3-month period to
make a recommendation to EPA regarding the petition. This 3-
month period will run concurrently with the 6-month review period
required under section 182(f)(3). The petitioner should submit
the petition and demonstration to the Administrator through the
appropriate EPA Regional Office.
The EPA encourages any petitioner to consult with the State
air quality agency and the appropriate EPA Regional Office during
the development of a section 182(f) demonstration. This is
necessary to ensure that the documentation provided (1) meets EPA
guidance, (2) does not conflict with similar analyses by the
State, and (3) is likely to be accepted by the State and EPA.
The EPA's decision to grant or deny a petition will include
consideration of the section 185B report and will be based on the
demonstration provided by the petitioner, the State's
recommendation, and the provisions of section 182(f). As noted
above, this document sets forth EPA's preliminary interpretations
of the section 182(f) provisions.
The EPA will provide notice of its final action on a
petition and the rationale for that action in a letter to the
petitioner within the 6 month period. In addition, EPA will
publish a notice describing the petition and EPA's determination
in the Federal Register. If EPA denies a petition, the
petitioner may supplement or revise the original petition at a
later date. Any revised petition would begin a new 6 month
period.
If EPA grants a petition, the section 182(f) NOX
requirements or portions of those requirements, would no longer
apply to those sources or areas, as described in EPA's approval
action. However, States remain free to adopt NOX restrictions
for other reasons. For example, a State may determine that NOx
reductions are needed for purposes of ozone maintenance planning,
ozone attainment in separate downwind nonattainment areas,
visibility protection, PM-10 control strategy, acid deposition
program or other environmental protection. The EPA could approve
certain NOx restrictions in a SIP revision despite granting a
petition under section 182(f), so long as the NOx restrictions
would not interfere with meeting any applicable requirement
concerning attainment and reasonable further progress or any
other applicable requirement of the CAA [see section 110(1)].
Section 182(f)(3) states that a person may petition the
Administrator for a determination under section 182(f) at any
time after the final report under section 185B is submitted to
Congress. The final section 185B report was sent to Congress by
the Administrator on July 30, 1993. Section 182(f)(3) also
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requires the Administrator to grant or deny such a petition
within 6 months after its filing with EPA.
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CHAPTER 3
NET AIR QUALITY BENEFIT
3.1 Demonstration
This demonstration applies to specific sources in an ozone
nonattainment area or in an ozone transport region. It must show
that NOX reductions from the sources seeking the exemption would
be counter-productive overall, considering the net air quality
benefits. Congress specified in this "test" for specific sources
a higher hurdle than in the other tests for areawide exemptions:
the demonstration must show a beneficial impact from the
avoidance of the NOx controls.
The procedure for this test is to first project areawide
baseline conditions that may be expected at the attainment
deadline (section 8.3). Then, analyses are conducted for 2
scenarios (section 3.4): with and without NOx reductions at the
sources concerned. As described in section 8.2, multi-year
analyses may also be conducted.
3.2 Factors
Unlike the tests described in chapters 4 and 5, the CAA does
not limit this test to consideration of ozone impacts. Instead,
this test is based on a broader set of air quality impacts
considered in the CAA. There are many air quality impacts
explicitly addressed in the CAA, both health and welfare related,
that may be directly or indirectly related to NOx emissions.
These impacts include ozone, nitrogen dioxide, and particulate
matter formation, visibility impairment, acid deposition, air
toxics formation, and nitrogen deposition in nutrient-sensitive
areas.
Due to the number and variety of impacts, it is generally
impractical or impossible to compare effects quantitatively from
one of these factors to those from another factor or among
several factors. For example, there is no readily available
scale to use to compare nitrogen dioxide impacts with acid
deposition impacts and/or visibility impacts. Thus, in order to
describe a method for determining the "net air quality benefit,"
a distinction must be made regarding which of the many factors
can and should be analyzed.
The EPA has concluded that the factors considered for the
purposes of section 182(f) must be consistent with the
requirements of the CAA. Thus, although "air quality impacts"
could potentially be defined in a very broad manner, EPA has
concluded that the air quality impacts considered under section
182(f) roust related directly to goals, standards, or mandates
that are explicitly addressed in the CAA. Therefore, the test
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8
for net air quality benefits must assure that a decision to grant
an exemption would not interfere with the achievement of the
specific programs or goals mandated in the CAA.
The primary test should be the effect the exemption would
have on attainment of the primary NAAQS for the criteria
pollutants. The primary NAAQS are set by the Administrator to
assure protection of the public health with an "adequate margin
of safety;" EPA has, thus, concluded that this test should focus
specifically on the effect of an exemption on the numbers of
exceedances of the primary NAAQS. A petitioner should model the
"NOx control" vs. "no NOx control" scenarios to assess the impact
the NOx controls would have on the numbers of exceedances of the
primary NAAQS, as described elsewhere in this document.
Secondary tests, as needed, can extend to the (qualitative
or quantitative) consideration of other air quality impacts that
are explicitly recognized in the CAA. These could include, for
example, the welfare effects which EPA has considered and deemed
necessary to protect against in setting secondary NAAQS for the
criteria pollutants. A petitioner could also consider any other
air quality effects that are explicitly addressed in the CAA
through goals, standards or mandates, for example, visibility or
air toxics emissions.
The CAA requires the NAAQS to be attained as expeditiously
as practicable and the CAA includes deadlines for rule adoption,
submittal of control strategies, and attainment of the primary
national ambient air quality standards (NAAQS). Thus, the
impacts on attainment of the primary NAAQS must be a primary
concern to this net air quality benefit test. In contrast,
impacts on nutrient-sensitive areas is an important environmental
issue that is addressed in the CAA, but does not have the same
detailed set of requirements and deadlines stated in the CAA as
do the NAAQS; thus, it should generally be a secondary concern to
this net air quality benefit test. Further, EPA is not aware of
any conflicts between the section 182(f) exemption and the
requirements of section 407, concerning acid deposition, that
might be considered in this analysis; i.e., granting a section
182(f) exemption would not relieve, conflict with, or otherwise
affect a source's obligation or ability to achieve NOx reductions
consistent with the section 407 requirements. In cases where NOx
reductions from a utility subject to section 407 would be
counterproductive to the net air quality benefit, EPA encourages
the State and utility to use the emission averaging provisions of
section 407 to achieve the required NOx reductions at a location
where they are not counterproductive to the net air quality
benefit. If any statutory conflicts are documented, they could
be considered on a case-by-case basis.
In all cases, the method for consideration of the net
benefits must be related primarily to "air quality" since section
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182(f) specifically requires a determination of the "air quality"
benefits. Thus, simpler tests, such as a "net emissions" test,
should not be relied upon since changes in emissions are not
necessarily directly related to changes in air quality. In
general, air quality impacts can be best determined by use of air
quality dispersion models. However, at the present time, there
are no EPA-recommended air quality dispersion models for
simulation of nitrate (particulate) formation or comparison among
ozone, nitrogen dioxide, and/or PM-10 NAAQS impacts in a single
nonattainment area.
In order to use air quality dispersion modeling whenever
possible and to avoid conflicts with other requirements of the
CAA, the methods described below should be used to determine the
net air quality benefit over an appropriate geographic area (see
section 3.3) which includes the ozone nonattainment areas
encompassing or nearby the sources concerned. These methods
include a primary consideration of the primary NAAQS air quality
benefits and secondary consideration of other air quality
benefits.
Ozone Nonattainroent Areas
For areas that are nonattainment only for ozone, the effects
of NOx reductions on ozone concentrations should be quantified
with currently available air quality modeling techniques (see
chapter 7). The net air quality benefit should be based on a
comparison of the geographic area exposed to concentrations above
the ozone NAAQS with and without NOx reductions from the sources
concerned.
Where Urban Airshed Model (UAM) results are available,
population exposure to concentrations above or near the NAAQS may
be used instead of the geographic area exposure factor. The
Regional Oxidant Model (ROM) results for NOx reduction scenarios
over major emissions/population centers should not be used
quantitatively for population exposure analyses. This is because
ROM results have their largest associated uncertainties in areas
where there is an inhomogeneous mix of emissions from major
sources. Since such areas also tend to have greatest
populations, use of the ROM, by itself, to estimate population
exposure may have considerable associated uncertainty.
It is important to note that EPA believes that photochemical
grid models such as UAM and ROM are not sufficient to assess
incremental changes to areawide ozone concentrations from
emissions reductions at a single or group of small sources.
Emission changes should amount to some significant fraction of
base emissions before modeling results with ROM or UAM can be
interpreted with sufficient confidence that the results are not
lost in the noise of the model and the input data.
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The EPA has reservations with respect to modeling NOx
reductions at a single source or group of sources unless the
modeling includes at least 10% of the domain-wide emissions.
Thus, this exemption analysis is appropriate for groups of large
emitters or for consideration of entire source categories, rather
than emission reductions at a single or group of small sources.
However, EPA will consider on a case-by-case basis an analysis
that considers less than a 10% change in the domain-wide
emissions. In such cases, the analysis of a small portion of the
emissions would show only a small difference in ozone
concentration, if any, between the with NOx and without NOx
scenarios, and, therefore, consideration of secondary factors
(described below) is particularly important in order to show a
net air quality benefit.
In some cases, the amount of emission reductions assumed in
the modeling analysis could be very large; thus, there may be
cases where the analysis does not result in any values above the
NAAQS for any pollutant and, thus, there would not be a
comparison of area or population exposed. This could occur even
though the difference in ozone concentration between the two
scenarios is large. In such cases, the petitioner should look to
the factors considered in the secondary test, such as welfare
effects or other air quality effects addressed by the CAA.
Areas Nonattainment for Both Ozone and Nitrogen Dioxide
For areas that are nonattainment for both ozone and nitrogen
dioxide, NOx reductions clearly are needed to provide for
attainment of the nitrogen dioxide standard, while either NOx or
VOC reductions (or both) might best provide for attainment of the
ozone standard. In such cases EPA would not make a finding of a
net air quality benefit since the CAA requires the NAAQS for
nitrogen dioxide to be met as expeditiously as practicable.
Areas Nonattainment for Both Ozone and PM-10
For areas that are nonattainment for both ozone and PM-10, a
determination is first needed if the secondary nitrates formed
from NOx emissions contribute significantly to the PM-10 NAAQS
violation(s) in the specific nonattainment area. This
significance determination is needed since, especially in the
eastern United States, EPA expects that the nitrate portion of
measured PM-10 will be found to be insignificant in many cases.
Where sufficient and reliable data exist to determine the nitrate
contribution to ambient PM-10 concentrations, this determination
may be limited to those NOx emissions sources subject to the
section 182(f) requirements. Where the contribution is
insignificant (see below), then the net air quality determination
should be based primarily on the ozone impacts. Where the
contribution is significant, EPA would not make a finding of a
net air quality benefit since the CAA requires the NAAQS for PM-
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10 to be met as expeditiously as practicable. For this purpose,
EPA intends to use its definition of a significant contribution
to a PM-10 nonattainment area which is 1.0 raicrograra per cubic
meter (nitrate and associated materials) for the annual standard
and 5 micrograms per cubic meter for the 24-hour standard (40 CFR
51.165).
Areas Nonattainment for Ozone and Carbon Monoxide,. Lead or
Sulfur Dioxide
For carbon monoxide, lead, and sulfur dioxide, EPA is not
aware of any significant impacts from NOx reductions. Therefore,
the net air quality benefits determination should be primarily
based on the ozone modeling analysis described above for areas
nonattainment for only ozone.
As noted above, equal consideration of all NOx impacts is
generally impractical in this net air quality benefit test
because of the lack of scales to compare the impacts among the
various factors. Nevertheless, additional factors explicitly
addressed in the CAA such as those listed below must be
considered at least on a qualitative basis in addition to any
information developed from the NAAQS analyses. Consideration of
the factors below is especially important in cases where the
analyses on the NAAQS pollutants cannot clearly determine the net
air quality benefit. In any case, EPA believes the amended CAA
places a substantial burden on the applicant to provide a clear
showing that NOx reductions would be counterproductive overall,
considering the net air quality benefits. Additional factors to
determine net air quality benefit may include but are not limited
to:
1. Effects associated with long-term exposures to plants,
animals, and materials.
2. Visibility impairment, long-term and episodic acid
deposition, air toxics, and deposition of nitrogen in
nutrient-sensitive watersheds.
3.3 Geographic Scope
In contrast to the other section 182(f) tests, the net air
quality benefit test is not specifically limited to an ozone
nonattainment area or ozone transport region and may be directed
at a specific set of sources. Thus, a very broad geographic area
should be considered. The area may, in some cases, extend beyond
an ozone nonattainment area or ozone transport region. In
addition, the area must not be so small that downwind impacts
from NOx emissions are not fully considered. Sufficient area is
needed to allow for completion and consideration of the various
chemical transformations of NOx and interaction with other
pollutants. At a minimum, the geographic area should include the
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ozone nonattainment area(s) encompassing or nearby the sources
concerned. For example, petitioning sources located in
attainment portions of the ozone transport region should analyze
their impact on nearby nonattainment areas and should consider
other factors, such as visibility impacts throughout the
surrounding area.
3.4 Scenarios
Section 182(f) states, for this test, that EPA must
determine that the net air quality benefits are greater in "the
absence of reductions of oxides of nitrogen from the sources
concerned." The procedure for this test is to first project
areawide baseline emissions that may be expected at the
attainment deadline (see sections 3.3 and 8.3). (As described in
section 8.3, multi-year analyses may also be conducted.) Second,
the projected baseline emissions are held constant, except for
the subject individual sources. Then, the air quality analyses
are conducted for these two scenarios:
1. the projected baseline emissions of VOC and NOx
(without NOx reductions from the sources concerned) and
2. the projected baseline emissions of VOC and NOx
emissions including NOx reductions at all emission
sources subject to the NOx NSR and RACT provisions of
section 182(f).
With respect to new major sources, the two scenarios should
take into account application of the section 182(f) NSR
requirements as described in section 8.5.
3.5 Sources
For this net air quality benefit test, the CAA refers to
"reductions of oxides of nitrogen from the sources concerned."
For purposes of this analysis, "the sources concerned" are
defined as the sources that would be exempted from the section
182(f) NOx requirements by the petition or State request. The
sources concerned may be identified in any of the following ways:
(1) specific individual sources, (2) one or more source
categories, or (3) a geographic area containing a group of
sources. As described in section 3.4, the sources concerned must
be analyzed together with other NOx and VOC sources in the area;
these other NOx sources should take into account application of
the section 182(f) RACT and NSR requirements (as part of the
areawide baseline conditions expected at the attainment deadline
year) since those NOx reductions are not the subject of the
exemption request.
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CHAPTER 4
CONTRIBUTE TO ATTAINMENT
4.1 Demonstration
This demonstration applies only to ozone nonattainment areas
that are not within an ozone transport region. The demonstration
must show that additional NOx reductions would not contribute to
ozone attainment in the area.
The procedure for this test is to utilize a photochemical
grid model (see chapter 7) to simulate several episode cases over
the nonattainment area under conditions that may be expected at
the attainment deadline (see section 8.2) considering three
emission reduction scenarios (see section 8.3): (1) substantial
VOC reductions; (2) substantial NOx reductions; and (3) both the
VOC and NOx reductions. If the areawide predicted maximum 1-hour
ozone concentration for each day modeled under scenario (1) is
less than or equal to that from scenarios (2) and (3) for the
same day, then the test is passed and the section 182(f)
requirements would not apply.
4.2 Episodes to Consider
In most ozone nonattainment areas it is likely that portions
of the area would benefit from NOx reductions and other portions
would not for each modeled day. The EPA believes it is
appropriate to focus this analysis on the areawide maximum 1-hour
predicted ozone concentration since this value is critical to the
attainment demonstration. In contrast, it should not be
necessary to examine the maximum 1-hour ozone concentrations at
each point modeled in the area since these points are not
necessarily important to development of the attainment
demonstration and since this is the only one of the section
182(f) tests which is not keyed to net benefits.
In certain ozone nonattainment areas it is possible
that NOx emission reductions may help to reduce the areawide
maximum predicted ozone concentration under some meteorological
conditions but not under others. The phrase "would not
contribute to attainment" could be interpreted to mean that NOx
emission reductions would not help reduce (I) any areawide
maximum 1-hour predicted ozone concentration, (2) the majority of
areawide maximum 1-hour predicted ozone concentrations, or
(3) the most severe areawide maximum 1-hour predicted ozone
concentration.
The EPA believes that the "majority" option is not
appropriate since this is the only one of the section 182(f)
tests which is not keyed to net benefits. Furthermore, (1) an
area may need to demonstrate attainment under multiple
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meteorological conditions, (2) generally a small number of
episodes will be modeled and (3) the NAAQS is based on multiple
exceedances rather than a single, most severe value. For the
above reasons, EPA believes this determination should be based on
each areawide maximum 1-hour predicted ozone concentration
modeled in accordance with this guidance (chapter 7). Thus, all
of the areawide maximum 1-hour predicted ozone concentrations
modeled must be greater with NOx reductions at the sources
concerned than without the reductions, or no exemption would be
granted. An area is not required to model all past exceedances;
only those episodes selected for modeling in accordance with EPA
guidance (chapter 7) need to be considered.
4.3 Geographic Scope
This demonstration focuses on attainment of the ozone NAAQS
"in the area." The EPA interprets this to mean, at a minimum, in
the nonattainment area. In contrast to the provision for
transport regions, which is likely to consider several attainment
and nonattainment areas in the section 182(f) analysis, this
demonstration is limited to consideration of the effects in a
single nonattainment area due to NOX emissions reductions from
sources in the same nonattainment area. However, since the
effects of an attainment strategy may extend beyond the
designated nonattainment area and since photochemical grid
modeling is necessary for this demonstration and is likely to use
a modeling domain larger than the nonattainment area, EPA
encourages States/petitioners to include consideration of the
entire modeling domain.
States should consider imposition of the NOx requirements if
needed to avoid adverse impacts in downwind areas, either intra-
or inter-State. States need to consider such impacts since they
are ultimately responsible for achieving attainment in all
portions of their State (see generally section 110) and for
ensuring that emissions originating in their State do not
contribute significantly to nonattainment in, or interfere with
maintenance by, any other State [see section 110(a)(2)(D)(i)(I)].
4.4 Applicability to Areas Requesting Redesicrnation to
Attainment
In some cases, an ozone nonattainment area might attain the
ozone standard, as demonstrated by 3 years of adequate monitoring
data, without having implemented the section 182(f) NOx
provisions over that 3-year period. Where the State submits a
request for redesignation to attainment along with necessary
supporting documentation and where NOx RACT and NSR requirements
were not implemented over that 3-year period, it is clear that
the section 182(f) language is met since "additional reductions
of oxides of nitrogen would not contribute to attainment." That
is, since attainment has already occurred, additional NOx
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reductions could not improve the area's attainment status and,
therefore, the section 182(f) demonstration could be approved.
Additional guidance on this subject is contained in a September
17, 1993 memorandum from Michael Shapiro to the EPA Regional
Offices regarding requests for redesignation to attainment.
The section 182(f) demonstration would not be approved if
there is evidence, such as photochemical grid modeling, showing
that the NOx exemption would interfere with attainment or
maintenance in downwind areas. As noted above, section 110
prohibits such impacts.
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CHAPTER 5
NET OZONE AIR QUALITY BENEFIT
5.1 Demonstration
This demonstration applies in an ozone transport region. It
must show that additional NOX reductions would not produce net
ozone benefits in the transport region. In this test the net
benefit must be demonstrated on a regionwide basis. Regionwide
includes all portions of the ozone transport region in which
impacts from NOx emissions from the area seeking the exemption
can be determined by the photochemical grid model.
The procedure for this test is to utilize a photochemical
grid model (see chapter 7) to simulate conditions that may be
expected at the attainment deadline (see section 8.3) considering
three emission reduction scenarios (section 8.4): (1)
substantial (se section 8.4) VOC reductions; (2) substantial NOx
reductions; and (3) both the VOC and NOx reductions. The net
ozone benefit may be determined by comparing the ozone
concentrations modeled in scenario (1) with results modeled from
scenarios (2) and (3). If the exposure to ozone concentrations
from scenario (1) is less than or equal to the exposure to ozone
concentrations from scenarios (2) and (3), then the section
182(f) net ozone benefits demonstration could be approved. As
described in section 8.3, multi-year analyses may also be
conducted.
5.2 Factors
The ozone NAAQS is set at 0.12 parts per million (ppm). In
defining "net ozone benefit," however, EPA recognized that
various forms of expression could be considered with respect to
ozone impacts. These forms include the 1-hour 0.12 ppm NAAQS, a
1-hour value less than 0.12 ppm, an 8-hour value set lower than
0.12 ppm, and a seasonal value set lower than the 0.12 ppm value.
However, ozone concentrations with different averaging periods
and values cannot readily be compared to each other. For
example, it is difficult to compare a set of 1-hour ozone peak
concentrations above 0.12 ppm against a set of 8-hour ozone peak
concentrations above 0.06 and determine which results are more
beneficial.
The EPA believes it is reasonable to focus the net ozone
benefits test on the 1-hour 0.12 ppm ozone NAAQS, where possible
for the following reasons: (1) the 0.12 ppm ozone NAAQS has been
set by the Administrator as the level necessary to protect the
most sensitive individuals from adverse health effects with an
"adequate margin of safety;11 (2) ozone concentrations with
different averaging periods and values cannot readily be compared
to each other, (3) the purpose of the various section 182
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provisions is primarily to attain the ozone NAAQS, and (4) it is
important for this guidance document to avoid any conflicts (as
noted in chapter 3) with the section 182 requirements.
Therefore, the averaging time to be used should be the one-hour
daily maximum ozone concentration and the analysis should focus
on values above the 0.12 ppm NAAQS level. Specifically, the net
ozone benefits test focuses on the total geographic area exposed
to ozone concentrations above the 0.12 ppm NAAOS level.
Where Urban Airshed Model (UAM) results are available,
population exposure to concentrations above or near the ozone
NAAQS may be used, instead of the geographic area exposure
factor. The Regional Oxidant Model (ROM) results for NOx
reduction scenarios over major emissions/population centers
should not be used quantitatively for population exposure
analyses. This is because ROM results have their largest
associated uncertainties in areas where there is an inhomogeneous
mix of emissions from major sources. Since such areas also tend
to have greatest populations, use of the ROM, by itself, to
estimate population exposure may have considerable associated
uncertainty.
Depending on the amount of NOx and VOC reductions selected
for each scenario, the model results in some cases might show all
scenarios to be below the 0.12 ppm ozone NAAQS level. In such
cases some might argue that there is no ozone benefit and, thus,
the NOx requirements should not apply. The EPA does not agree
with such an interpretation because the CAA specifies "net ozone"
rather than "ozone attainment" for this test. In fact, a "net"
ozone test is necessary to integrate the benefits and disbenefits
of NOx reductions that are likely to vary from grid to grid in a
given analysis area. That is, NOx reductions may reduce hourly
ozone concentrations in some locations and increase hourly ozone
concentrations in other locations within the same modeling
domain. Therefore, a broader factor is needed than the areawide
0.12 ppm where the modeled scenarios show all values below the
ozone NAAQS.
Consideration of ozone air quality impacts other than the
primary NAAQS values is appropriate as a secondary factor. Thus,
values such as the following are appropriate for consideration
where no conclusion can be drawn through the above analysis based
on the ozone NAAQS values: effects associated with long-term
exposures to ecosystems, crops, animals, and materials.
5.3 Attainment/Unclassified Portions
The section 182(f)(l)(B) demonstration explicitly refers to
nonattainment areas within an ozone transport region. The CAA
does not clearly state whether or not portions of ozone transport
regions that are attainment/unclassified can make the net ozone
benefit demonstration. The section 182(f)(l) net air quality
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benefit test is available to any area; however, as noted
previously it is a higher hurdle. Thus, while a severely
polluted area might be able to demonstrate that NOX reductions do
not apply because the "net ozone benefits" test is satisfied, the
CAA could be interpreted to require NOX reductions in the
surrounding attainment area because that area cannot meet the
same test. It is unlikely that Congress intended such a result.
An alternative reading of the CAA can be found through
section 184(b)(2). This provision states that the attainment/
unclassified portions of the transport region must meet "the
requirements which would be applicable to major stationary
sources if the area were classified as a moderate nonattainment
area." Thus, the CAA could be interpreted to provide the same
section 182(f)(l)(B) demonstration process for these attainment/
unclassified areas, since they should be treated as moderate
nonattainment areas for the purpose of applying the section
182(f) requirements and moderate nonattainment areas in the
transport region are eligible to meet the "net ozone benefits"
test.
Even without that language, EPA would be inclined to allow
an attainment/unclassified area in a transport region to satisfy
the "net ozone benefits" test. It would be absurd, and therefore
it is unlikely that Congress intended to apply more stringent
requirements in the attainment/unclassified portions of the
transport region than would apply to the more severely polluted
portions. Congress apparently did not intend any lesser
requirements to apply in the attainment/unclassified portions of
the transport region. The EPA believes that it is appropriate to
extend the section 182(f) provision beyond the boundaries of a
nonattainment area into adjacent attainment/unclassified areas
which are part of the same section 182(f) demonstration. Thus,
where a State/petitioner demonstrates that NOx reductions would
not produce net ozone benefits in the transport region, then the
section 182(f) NOx requirements would not apply to those sources
or areas as described in EPA's approval action. Such a
demonstration must include all portions of the ozone transport
region in which impacts from NOx emissions from the area seeking
the exemption can be determined by the photochemical grid model.
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CHAPTER 6
EXCESS EMISSIONS REDUCTIONS
6.1 General
Section 182(f)(2) provides the flexibility to limit the
scope of the NOx NSR and RACT requirements. Application of the
NOx NSR and/or RACT requirements can be limited to the extent
that any portion of those reductions are demonstrated to result
in "excess reductions." The tests for demonstrating excess
reductions are generally the same as in section 182(f)(l): net
air quality benefit, contribute to attainment and net ozone
benefit. However, in this case, the demonstration must show that
a portion of the otherwise required NOx reductions are either
counterproductive to the net air quality, do not contribute to
attainment, or do not provide a net ozone benefit [depending on
the section 182(f) test applied].
As described below, for the contribute to attainment or net
ozone tests, the excess reductions test must show that certain
NOx reductions are in excess of the reductions specified in
either the attainment demonstration required by section 182 and
contained in the approved SIP or an attainment demonstration
adopted by the State to meet the section 182 attainment
demonstration requirement and submitted to EPA for approval. The
excess emission reductions may be described, for example, as (1)
an areawide across-the-board tonnage reduction; (2) emissions
attributed to specific sources; or (3) emissions from a
geographic portion of the nonattainment or transport area.
6.2 Demonstration
The "contribute to attainment" and "net ozone benefit" tests
described in chapters 4 and 5 both require an areawide or
regional analysis. In such areawide/regional analyses, NOx
emission reductions at a large number of sources are considered.
These analyses are appropriate to determine in a directional
manner whether or not NOx reductions are expected to be
beneficial with respect to the air quality in the area/region.
The analyses described in chapters 4 and 5 may be less precise
than an attainment demonstration required under section 182(c).
The EPA believes that the excess reductions provision
requires a more precise analysis; specifically an analysis which
is based on the attainment demonstration. That is, the excess
reductions provision must be more than a directional finding on
an areawide basis. Under the excess reductions provision, an
analysis is needed to show that a specific portion of the total
areawide NOx emissions is not beneficial under one of the three
tests. Thus, individual or groups of sources may petition to
show that, while NOx reductions may be beneficial directionally
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in the area, NOx reductions from their specific sources are not
beneficial and, thus, should be exempt from the NOx requirements.
Without providing some constraints in this guidance
document, the excess reductions provisions could undermine the
section 182(f) requirements, since each individual emission
source could theoretically petition for an exemption with the
argument that their small contribution to the overall ozone
problem is inconsequential. Such a petition might be considered
consistent with the analyses required in chapters 4 and 5, since
an exemption may be granted where the modeled NOx reductions show
no impact on ozone concentrations. Certainly, if EPA allowed
very small amounts of NOx reductions to be modeled individually,
this interpretation would create a significant loophole.
Congress would not have intended, and therefore EPA does not
accept the argument, that the owner/operator of one car or one
small boiler can be excused from the CAA requirements because
their emissions, viewed alone, are small. Considered together
with other small contributions, the emissions may be important to
attainment. That is, emissions from one car or one commercial
boiler would not change the areawide ozone concentration, yet
together with other cars or boilers, they may be critical to the
area's attainment strategy. Furthermore, as previously
described in this document, ozone air quality models should not
be applied solely to determine the incremental effect of small
sources as such emissions could be lost in the noise of the air
quality model and emissions inventory uncertainties when
considered alone.
For the above reasons, EPA has determined that the excess
reductions demonstration for the "contribute to attainment" or
"net ozone benefits" tests must be tied to the area's SIP
attainment demonstration. Thus, this test must show that the
excess reductions are reductions in excess of those specified in
the attainment demonstration required by section 182 and either
contained in the approved SIP or as adopted by the State to meet
the section 182 attainment demonstration requirement and
submitted to EPA for approval. This tie to the attainment
demonstration assures that an excess reductions petition would
not arbitrarily be based on small emissions and would not
undermine the State's control strategy.
In contrast, the "net air quality benefit" test discussed in
chapter 3 is intended to address an individual or small number of
sources and already has an adequate constraint. The net air
quality benefit test requires a showing that NOx reductions
specifically from the sources concerned are counterproductive.
The net air quality benefit test imposes a higher hurdle than the
other two tests and EPA believes this higher hurdle is adequate
for purposes of the excess emissions test as well.
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CHAPTER 7
MODELING TECHNIQUES
7.1 Photochemical Grid Modeling
As described in chapters 3-6, photochemical grid modeling is
generally needed to document cases where NOx reductions are
counterproductive to net air quality (chapter 3), do not
contribute to attainment (chapter 4), do not show a net ozone
benefit (chapter 5), or include excess reductions (chapter 6).
As described below, the Urban Airshed Model (UAM) or, in an ozone
transport region, the Regional Oxidant Model (ROM) are acceptable
models for these purposes.
The EPA investigated the feasibility and acceptability of
applying relatively inexpensive screening techniques to evaluate
if NOx control measures are likely to be beneficial with respect
to attainment of the ozone NAAQS (Langstaff and Scheffe, 1991).
However, EPA determined that, as a technical matter,
photochemical grid modeling is the only reliable tool to justify
an areawide exemption from the NOx requirements.
The EPA's reliance on photochemical grid models is supported
by the recently published findings of the NAS on tropospheric
ozone (December 1991). The NAS report concluded that three-
dimensional or grid-based ozone air quality models are currently
the best available models for representing the chemical and
physical processes of ozone formation. The report provides a
list of such models (Table 10-1), including UAM and ROM. The NAS
report also states that "ROM is the only regional model available
for assessment of control strategies for urban and rural ozone in
the eastern United States" (page 365).
The 1990 CAA requires the use of gridded models in many
ozone nonattainraent areas. In 1990, EPA released an updated
version of the UAM, reflecting numerous advances in
photochemistry and numerical solution techniques which emerged
during the 1980s. An extensive multi-volume UAM User's Manual
was prepared to facilitate operation of the UAM. Guidance on
regulatory application of the UAM was completed in July 1991.
Several efforts are underway to improve pre- and post-processing
UAM capabilities and train the States in applying the model.
The EPA encourages applications of advanced modeling methods
where they are found to be more appropriate. Such methods may be
acceptable on a case-by-case basis after (1) preparation of a
modeling protocol, (2) proper testing and evaluation, and (3)
approval by the appropriate EPA Regional Office.
Less sophisticated models, such as EKMA, lack the detailed
treatment/consideration of physical orientation of NOx sources
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and dispersion of their plumes. Further, since trajectory models
only address a limited number of trajectories, they cannot assess
whether NOx control contributes to attainment at all locations in
an ozone nonattainment area. Therefore, such models are
insufficient and not acceptable for the section 182(f)
demonstration.
7.2 Urban Airshed Model
UAM results are acceptable for the purpose of the section
182(f) demonstrations. Application of UAM should be consistent
with techniques specified in the EPA "Guideline on Air Quality
Models (Revised)." Further, application of UAM should also be
consistent with procedures contained in the EPA "Guideline for
Regulatory Application of the Urban Airshed Model" (July 1991).
Thus, episode selection for the section 182(f) demonstration
should be consistent with the UAM guidance for SIP attainment
demonstrations. An assessment of the model's performance and a
copy of the modeling protocol should be included in the analysis
for informational purposes.
7.3 Regional Scale Modeling
In an ozone transport region, the net ozone benefits test
should be met by use of regional scale modeling. Regional scale
modeling is needed since the section 182(f) language explicitly
refers to net ozone benefits "in such region." Regionwide or
regional scale modeling includes all portions of the ozone
transport region in which impacts from NOx emissions from the
area seeking the exemption can be determined by the photochemical
grid model. Prior to the availability of ROM and/or UAM results
supporting the section 182(c) attainment demonstrations, the
EPA's "Regional Ozone Modeling for Northeast Transport" study
(June 1991) is an acceptable basis for this demonstration. When
more recent ROM and/or UAM regionwide studies for the Northeast
Ozone Transport Region have been completed and are available,
they must be used for any section 182(f) demonstration.
Where UAM studies have been completed and are available, ROM
results are acceptable for evaluating effects outside of the UAM
modeling domains established pursuant to attainment demonstration
requirements for section 182. Thus, ROM results are acceptable
for evaluating effects in portions of a transport region outside
of the UAM modeling domain for the purpose of a section 182(f)
demonstration. It is not appropriate, however, to use ROM to
assess the effects in an individual city outside of any UAM
domain. ROM is most suitable for assessing composite impacts
over large areas (which may include individual cities) where UAM
results are unavailable. Results of available ROM applications
are archived on the EPA's Gridded Model Information Support
System (GMISS).
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7.4 Model Results and SIP Interface
Where a petition for an exemption [section 182(f)(l)] or
excess reductions determination [section 182(f)(2)] is granted by
EPA prior to adoption and submittal of the State's rules, the
State may simply choose not to submit the NOx rules. If a
petition is granted after submittal of the NOx rules, but prior
to EPA approval, the State may choose to withdraw the rules and
preclude further EPA action. In a case where a petition is
granted ("exempted area") after EPA approves of the NOX rules,
the SIP would need to be modified through a SIP revision to
rescind the NOX rules provided such rescission would not
interfere with attainment or reasonable further progress
[section 110(1)].
Following application of a photochemical grid model that is
required for serious and above areas to support the attainment
demonstrations due by November 1994, a State must select and
adopt a control strategy that provides for attainment as
expeditiously as practicable, but no later than the date
prescribed in section 181. This decision must be addressed by a
State whether or not an area was exempted from the November 1992
subraittal of NOX RACT and/or NSR rules and may result in revision
of the previously adopted rules. In some instances the NOX RACT
and NSR requirements already adopted may need to be supplemented
with additional or more advanced NOX controls in order for the
area to attain the NAAQS.
In other cases, an area initially exempted may choose, based
on the new photochemical grid modeling results, to adopt certain
NOX reduction rules in order to attain and/or meet reasonable
further progress requirements through NOX substitution. The area
would be removed from "exempt" status since NOx reductions were
subsequently found to be beneficial in their ozone attainment
plan. Consequently, the area would have to adopt the NOX RACT
and NSR rules except to the extent modeling shows that the
controls beyond those chosen are "excess reductions" (chapter 6)
or are counterproductive to the net air quality (chapter 3).
Credit for NOX substitution would be granted only if in
accordance with the EPA guidance. In any event, these changes
must be submitted as a SIP revision and must provide for
attainment as expeditiously as practicable and meet reasonable
further progress requirements.
Alternatively, for an area that adopted the NOX RACT and NSR
rules as required by section 182 (i.e., not exempt), a State may
choose to revise some or all of those rules to require less NOX
stationary source controls. This action would be based on the
application of a photochemical grid model showing that the
subject NOX controls result in excess emission reductions, as
determined using the section 182(f) tests set forth at the
beginning of this section. The revisions must be submitted as a
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24
SIP revision and the SIP must demonstrate attainment as
expeditiously as practicable.
7.5 Other Analytical Techniques
Guidelines on analytical techniques for assessing other air
quality impact factors, such as acid deposition, population
exposure or visibility, are not readily available. Therefore,
EPA encourages petitioners to consult with the State and EPA
Regional Office to agree on an acceptable methodology on a case-
by-case basis.
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CHAPTER 8
EMISSIONS ANALYSIS
8.1 General
As described in chapters 3-6, photochemical grid modeling is
needed to document cases where NOx reductions are
counterproductive to net air quality (chapter 3), do not
contribute to attainment (chapter 4), do not show a net ozone
benefit (chapter 5), or include excess reductions (chapter 6).
Application of these models requires the use of a representative
emissions inventory. This chapter describes the emission
inventory requirements for the various section 182(f)
demonstrations.
8.2 Biogenic Volatile Organic Compound fVOC^ Emissions
The NAS report states that, in some cases, "without control
of NOx emissions, this VOC background should be able to generate
ozone concentrations that exceed the NAAQS concentration of 120
ppb" (page 244). Biogenic emissions can influence both the
nature (i.e., VOC or NOx) and extent of required emissions
controls. Therefore, inclusion of biogenic emissions are
necessary inputs to model applications which assess the roles of
VOC and NOx in ozone formation for purposes of section 182(f).
In estimating biogenic emissions, the most recent version of the
Biogenic Emissions Inventory System (BEIS) (available through the
EPA Regional Offices) should be used.
8. 3 Years to Analyze
In general, the purpose of the section 182(f) requirements
for NOx is related to attainment of the ozone standard. This
suggests an analysis that is focussed on the time that attainment
of that standard is required. In addition, other sections of the
CAA require moderate and above ozone nonattainment areas to
develop modeling analyses which demonstrate attainment by the
appropriate statutory deadline; to the extent that such modeling
analyses are already underway, they could be useful for the
section 182(f) demonstration also.
Considering these points, EPA believes that the 182(f)
demonstrations should, at a minimum, reflect conditions expected
at the time the subject area is required to attain the ozone
standard. For example, in a serious ozone nonattainment area,
the year would be 1999. As described in section 8.5, the
conditions should also be consistent with assumptions contained
in the SIP. Thus, base year emissions would be projected to the
year reflecting the attainment deadline and would include growth
in VOC and NOx emissions as well as CAA-mandated VOC emission
reductions. Specific emission scenarios with and without NOx
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26
reductions would be built upon this projected emissions baseline
as described elsewhere in this document. In addition, as
described later in this section, multi-year analyses may also be
conducted.
In an ozone transport region, a section 182(f) demonstration
would likely cover an area which includes ozone nonattainment
areas of more than one classification, and thus more than one
attainment deadline. For example, a metropolitan area may have a
higher classification than a nearby rural nonattainment area.
For these areas, it is possible that NOx reductions may be
beneficial to attainment in the near term with respect to the
rural nonattainment area (and lesser classification deadline)
but, at the same time or in a longer tiraeframe, NOx reductions
might be shown to be not beneficial when considering the area as
a whole (since NOx reductions are generally expected to be more
beneficial in rural areas). In order to determine whether the
NOx reduction requirements should apply, EPA believes that, at a
minimum, the section 182(f) demonstration should reflect
conditions expected at the latest attainment deadline for the
area as a whole. In addition, States should consider imposition
of the NOx requirements if needed to avoid adverse impacts in
downwind areas, either intra- or inter-State. States need to
consider such impacts since they are ultimately responsible to
provide for attainment in all portions of their State and must
not contribute significantly to nonattainment in, or interfere
with maintenance by, any other State.
Alternatively, the State/petitioner may include a multi-year
analysis in its section 182(f) demonstration. This is
appropriate for areas demonstrating either a net air quality
benefit or a net ozone benefit. In these demonstrations, the
analysis may include periodic assessments of the effects of NOx
reductions and integrate those effects to arrive at a finding on
whether or not NOx reductions are beneficial. For example, an
area may develop geographic area exposure analyses for each year
or for every third year up to the attainment year and assess the
overall impact of NOx reductions from that information.
8.4 Scenarios to Compare
For the contribute to attainment and net ozone benefit
tests, the projected emissions should, at a minimum, consider
three scenarios which vary emission reductions from anthropogenic
sources: (1) substantial VOC reductions; (2) similar NOx
reductions; and (3) both the VOC and NOx reductions. Total
emissions to model include both anthropogenic and biogenic
emissions.
In contrast to the net air quality demonstration (chapter 3)
which focuses on the scenario "in the absence of reductions of
oxides of nitrogen from the sources concerned," the contribute to
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27
attainment and net ozone benefit demonstrations concern an
unspecified "additional reductions" of NOx. Thus, while the net
air quality benefit test must focus on NOx reductions due to NSR
and RACT, the other demonstrations may more broadly consider NOx
reductions, including reductions that employ advanced control
technology (i.e., beyond RACT). The application of the VOC and
NOx reductions should be as source category specific as possible,
rather than across-the-board, in order for the results to be most
useful.
In the first scenario the demonstration should use the VOC
reductions needed to attain (demonstrated by EKMA or UAM
analyses). Alternatively, if the attainment demonstration has
not been completed, the demonstration may use some other
substantial VOC reduction. Reductions associated with attainment
are appropriate for the reasons described above. In any case,
the VOC reductions should be substantial and documented as
reasonable to expect for the area due to the CAA requirements.
For example, a minimum of a 40% anthropogenic VOC reduction
areawide from the 1990 emission inventory may be reasonable to
expect for serious areas, considering motor vehicle emission
controls, inspection/maintenance, reasonable further progress and
other CAA requirements.
In the second scenario, NOx reductions should be modeled
without any VOC reductions above the attainment year baseline.
The level of NOx reductions should reflect the same percent
reduction of anthropogenic VOC emissions in scenario (1) above.
It is important to model this case since NOx reductions, instead
of additional VOC reductions, may show a clearer benefit.
In the third scenario, a similar level of NOx reductions
would be modeled along with the level of VOC reductions chosen.
That is, if a 40% VOC reduction is chosen in scenario (1), then
the model for scenario (3) would simulate a 40% VOC reduction and
approximately a 40% NOx reduction. It would be inappropriate to
select a high level of VOC reductions and a low level of NOx
reductions since this could artificially favor a finding that NOx
reductions are not beneficial; the two levels should be similar.
8.5 Consistency with the SIP
Any section 182(f) demonstration must include a showing that
the exemption request uses assumptions that are consistent with
requirements of the SIP and the CAA. It is possible that a
petition could demonstrate that, under some circumstances, NOx
reductions are not needed to attain the ozone standard. However,
unless the state actually adopts those particular circumstances
into its SIP, there is no assurance that the petition's analysis
is valid. That is, if the assumptions contained in the
petitioner's demonstration are not valid, the conclusions are
similarly not valid and EPA would not approve the petition. The
section 182(f) petition process should not undermine the State's
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28
implementation plan. The petition should reflect measures
consistent with mandatory CAA requirements, federally-approved
SIP requirements, and recent SIP revisions adopted by the State
and submitted to EPA for approval. The EPA encourages
petitioners to coordinate these analyses with the appropriate
State(s) as they are being developed.
8.6 New Source Review
The section 182(f) exemption provisions center on the effect
on ozone concentrations due to NOx emission reductions. With
respect to RACT, which involves emissions reductions from
existing sources, this is a perfect fit. In the case of new or
modified sources, however, other factors should be considered.
Even after the application of on-site controls appropriate for a
major new or modified source, the source will, considered alone,
result in major increases in NOx emissions. However, the NSR
offset provisions would require the new source to obtain emission
reductions from other sources so as offset any emissions increase
associated with the new source.
To take into account the full impact of the NSR program, the
term "NOx reductions" must be carefully interpreted. When
considering the air quality impacts in chapters 3-6 of this
document "with NOx reductions" or with "substantial NOx
reductions," the analysis should reflect a zero emissions
increase from stationary sources after November 15, 1992 due to
the NSR offset requirement; when considering the "without" NOx
reductions scenarios, the analysis should include NOx emission
increases after November 15, 1992 due to new or modified
stationary sources of NOx, many of which would be subject to the
best available control technology requirement through the
prevention of significant deterioration program, but not to
offsets.
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86
D-7
Nitrogen Oxides (NOx) Reasonably Available Control
Technology for the Repowering of Utility boilers
(March 9, 1994)
This memorandum provides guidance on the determination of
NOx RACT in cases where a utility commits to repower its boiler
in the near future.1 The guidance is intended primarily for use
by State and local air pollution control agencies as they develop
and adopt NOx RACT rules for incorporation into their State
implementation plans as required under section 182 of the Clean
Air Act. The guidance is generally applicable to other source
categories including turbines and process heaters.
111 Repower ing" is defined in section 402 of the Act and
generally means the replacement of an existing boiler with a
technology capable of controlling multiple combustion emissions
simultaneously with improved boiler or generation efficiency and
with significantly greater waste reduction relative to the
performance of technology in widespread commercial use as of
November 15, 1990.
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March 9, 1994
MEMORANDUM
SUBJECT
FROM:
TO:
Nitrogen Oxides (NOx) Reasonably Available Control
Technology (RACT) for the Repowering of Utility Boilers
John S. Seitz, Director
Office of Air Quality Planning and Standards (MD-10)
Director, Air, Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
This memorandum provides guidance on the determination of
NOx RACT in cases where a utility commits to repower1 its boiler
in the near future. The guidance is intended primarily for use
by State and local air pollution control agencies as they develop
and adopt NOx RACT rules for incorporation into their State
implementation plans (SIP's) as required under section 182 of the
Clean Air Act as amended in 1990 (Act).
Several States have included specific provisions in their
proposed NOx RACT rules for utilities which intend to repower
their boilers in the near future and that will meet emissions
limitations based on advanced control technologies. The
following specific issues are addressed in this memorandum:
1 "Repowering" is defined in section 402 of the Act and
generally means the replacement of an existing boiler with a
technology capable of controlling multiple combustion emissions
simultaneously with improved boiler or generation efficiency and
with significantly greater waste reduction relative to the
performance of technology in widespread commercial use as of
November 15, 1990.
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1. Must sources which intend to repower meet the
May 31, 1995 RACT compliance date?
2. How will the RACT requirements be met for the interim
period between 1995 and 1999?
3. Are repowering provisions applicable to other source
categories?
Must sources which intend to repower meet the May 31. 1995
RACT compliance date?
The Act requires RACT to be implemented at major NOx sources
by May 31, 1995 [see section 182(b)(2)(C) and 182(f) ]. Utility
boilers that are intended to be repowered are subject to the same
requirement to implement RACT by May 31, 1995. However, the
State's determination of what constitutes RACT could include
consideration of a utility's commitment to repower. In that
case, the State's RACT analysis would focus on the technical and
economic feasibility of controls available over the interim
period between May 31, 1995 and the repowering date. If a State
wants to incorporate into its NOx RACT rules a procedure for
utilities that intend to repower, the rules must meet the
requirements described below.
1. The SIP revision must require the utility to submit to
the State an enforceable commitment to repower and an analysis
that defines RACT for the unit for the interim period of time
between May 31, 1995 and the date the unit will be repowered
("interim RACT11) .
2. The commitment must include the date by which the
utility will repower, as well as compliance dates for the
following repowering milestones: (a) the date by which contracts
for the repowering project will be awarded, or by which orders
will be issued for the purchase of component parts to accomplish
the repowering project; (b) the date of initiation of on-site
construction or installation for the repowering project; and (c)
the date by which on-site construction of the repowered unit is
completed.
3. The State must adopt and submit the commitment to
repower and the interim RACT requirements to the Environmental
Protection Agency (EPA) by November 15, 1994 as a source-specific
SIP revision. A SIP revision is needed to make the commitment
and interim RACT requirements federally enforceable. As an
alternative to a source-specific SIP revision, States may make
the repowering and the interim RACT requirements enforceable by
including them directly in the NOx RACT rule for a boiler type.
In this case, the State must justify, when the rule is formally
submitted to EPA, that the interim requirements constitute RACT
for the given boiler type.
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4. The SIP revision must require that the utility boiler
complies with the interim RACT requirements by May 31, 1995.
5. The SIP revision must require that the utility boiler be
repowered no later than May 31, 1999 and must meet all applicable
SIP and Federal requirements. For example, if a State adopts NOx
emissions limits for utility boilers for purposes of attaining
the ozone standard, the repowering source must meet those
emissions limits consistent with the SIP timeframes. Further,
the repowering source must meet any applicable Federal new source
requirements consistent with EPA guidance and regulations.
How will the RACT requirements be met for the interim period
between 1995 and 1999?
In the interim RACT analysis, the utility should document
the cost, cost effectiveness, and emissions reductions of all
technologically feasible controls. In the determination of cost
effectiveness, however, the utility may annualize controls over
the period of time between May 31, 1995 and the date the unit
will be repowered, to the extent it is shown that the controls
installed to meet the May 31, 1995 deadline have no usefulness
once the unit is repowered.
For example, if a wall-fired coal boiler is going to be
repowered to a combined-cycle turbine, then low-NOx burners may
be assumed to have no useful life beyond the date that the
facility is committing to repower. Thus, in the determination of
the cost effectiveness of the low-NOx burners, costs could be
annualized over a shorter period of time than their normal useful
life. In some cases, the shorter period could result in cost
effectiveness for the low-NOx burners that is so high it would be
considered economically infeasible.
On the other hand, if certain controls will be useful once
the unit is repowered, the cost of these controls cannot be
annualized over a shortened period of time. For example, reburn
at a cyclone boiler might be considered for purposes of
determining the interim RACT requirement. In this case, the cost
of installing a natural gas pipeline for the cyclone boiler could
not be annualized over a shortened period of time if the boiler
is going to be repowered to a combined-cycle turbine that will
utilize natural gas. That is, only the cost of installing the
pipeline early can be attributed to the cost to meet RACT by
May 31, 1995. Therefore, it is important that the State require
that the facility's analysis describe the repowering project in
detail so the effects on the useful life of RACT controls can be
correctly evaluated.
In some cases, all combustion modifications and add-on
controls might be shown to be technically or economically
infeasible for the interim RACT requirement. In such cases,
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other techniques should be considered, such as derating or boiler
tune-ups, to achieve NOx emissions reductions in the interim
period.
As described above, the State must adopt and submit by
November 15, 1994 a commitment to repower a utility boiler as
well as interim RACT requirements for that boiler as a SIP
revision. Thus, the commitment and interim RACT requirements
would be enforceable by the State and, upon approval, by EPA. If
the commitment were not enforceable, then the NOx RACT
determination would not be valid since it relies on the
repowering commitment.
Are repowering provisions applicable to other source
categories?
States may extend the guidance contained above to other
source categories, including stationary internal combustion
engines, gas turbines, and process heaters.
In summary, this guidance provides that, under certain
circumstances, States may meet the amended Act's NOx RACT
requirements by adopting rules which establish "interim RACT"
requirements for sources that must be implemented by May 31,
1995, and establish a near term date by which the source will
meet emissions limitations based on advanced control
technologies, such as in the case of utility repowering. If you
have questions on this memorandum, please contact Doug Grano of
my staff at (919) 541-3292.
cc: Kent Berry
NOx Work Group
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91
D-8
Cost-Effective Nitrogen Oxides (NOx) Reasonably
Available Control Technology
(3-16-94)
This memorandum provides guidance for determining NOx RACT
as it relates to nonutility sources and utility boilers which
were not addressed by the Environmental Protection Agency's
(EPA's) previous guidance. The NOx supplement to the general
preamble (November 25, 1992, 57 FR 55625) identifies emission
rates that presumptively meet the NOx RACT requirement for
tangential and dry bottom wall-fired utility boilers. The
guidance goes on to state that, for other major NOx sources, EPA
expects that NOx RACT will be set at levels that are "comparable"
to the levels specified for tangential and dry bottom wall-fired
utility boilers. The guidance states that: "Comparability shall
be determined on the basis of several factors including, for
example, cost, cost-effectiveness, and emission reductions."
This memorandum primarily addresses one of the factors in a NOx
RACT determination—cost effectiveness—and provides guidance on
how to determine which control techniques are of "comparable
cost-effectiveness for NOx RACT." In addition, this memorandum
provides limited discussion of other factors, including emission
reductions.
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March 16, 1994
MEMORANDUM
SUBJECT: Cost-Effective Nitrogen Oxides (NOx) Reasonably
Available Control Technology (RACT)
FROM: D. Kent Berry, Acting Director
Air Quality Management Division (MD-15)
TO: Director, Air, Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
This memorandum provides guidance for determining NOx RACT
[required by section 182(f) of the Clean Air Act (Act)] as it
relates to nonutility sources and utility boilers which were not
addressed by the Environmental Protection Agency's (EPA's)
previous guidance. The document entitled, "State Implementation
Plans; Nitrogen Oxides Supplement to the General Preamble; Clean
Air Act Amendments of 1990 Implementation of Title I; Proposed
Rule," (NOx supplement) (November 25, 1992, 57 FR 55625)
identifies emission rates that presumptively meet the NOx RACT
requirement for tangential and dry bottom wall-fired utility
boilers. The guidance goes on to state that, for other major NOx
sources, EPA expects that NOx RACT will be set at levels that are
"comparable" to the levels specified for tangential and dry
bottom wall-fired utility boilers. The guidance states that:
"Comparability shall be determined on the basis of several
factors including, for example, cost, cost-effectiveness, and
emission reductions." This memorandum primarily addresses one of
the factors in a NOx RACT determination—cost effectiveness—and
provides guidance on how to determine which control techniques
are of "comparable cost-effectiveness for NOx RACT." In
addition, this memorandum provides limited discussion of other
factors, including emission reductions.
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It should also be noted that, in certain areas, States may
require NOX controls based on advanced control technologies;
i.e., control technologies that reduce emissions beyond RACT or
title IV (acid rain) requirements. For example, advanced
controls would be required as part of a serious ozone
nonattainment area's 1994 State implementation plan if modeling
found such controls to be necessary to provide for expeditious
attainment of the ozone national ambient air quality standards.
In order to avoid or minimize potentially incremental or
repetitive control requirements. States and regulated sources
should consider in advance the implications of all relevant
requirements.
In general, the actual cost, emission reduction, and cost-
effectiveness levels that an individual source will experience in
meeting the NOx RACT requirements will vary from unit to unit and
from area to area. These factors will differ from unit to unit
because the sources themselves vary in age, condition, and size,
among other considerations. The EPA's general RACT guidance
urges States to judge the feasibility of imposing specific
controls based on the economic and technical circumstances of the
particular unit being regulated. In many cases, these factors
are not the same in all States since the specific NOx RACT
emission limitations and averaging times will differ from State
to State. The EPA's presumptive NOx RACT levels for certain
utility boilers are based on capabilities and problems which are
general to the industry on a national basis. States may adopt
statewide NOx RACT levels which are more stringent than the EPA
levels based on statewide industry conditions. For these
reasons, a single cost, emission reduction, or cost-effectiveness
figure cannot fully describe the NOx RACT requirement. Thus, the
information provided in this memorandum does not prescribe a
single cost-effectiveness figure, but rather provides additional
guidance which States may use as they make NOx RACT
determinations.
For NOx RACT, cost effectiveness is a figure in dollars per
ton of NOx emissions reductions per year. In order to clarify
the "comparable cost-effectiveness for NOx RACT" referred to in
the NOx supplement, EPA reviewed the December 1992 EPA/Northeast
States for Coordinated Air Use Management (NESCAUM) report
(EPA/NESCAUM report) on utility boilers entitled, "Evaluation and
Costing of NOx Controls for Existing Utility Boilers in the
NESCAUM Region11 (EPA 453/R-92-010). This report identifies
various NOx control technologies for existing utility boilers and
their associated costs, cost effectiveness, and emission
reductions. As described below, EPA has extracted from the
report the cost effectiveness of controls that are expected to
meet the EPA's presumptive NOx RACT for tangential and dry bottom
wall-fired utility boilers at least cost. These cost figures
generally define the "comparable cost-effectiveness for NOx RACT"
referred to in the NOx supplement.
The November 1992 NOx supplement to the General Preamble
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specifies the following areawide presumptive NOx RACT emission
limits (Ibs NOx per million Btu determined on a rolling 30-day
average) for utility boilers:
Coal: tangential—0.45 wall—0.50
Gas/Oil: tangential—0.20 wall—0.30
Technologies available to meet these NOx RACT levels are
described in section 4 of the EPA/NESCAUM report. Section 5 of
that report describes the cost algorithm used, which includes
consideration of process capital equipment, total plant cost and
investment, fixed and variable operating cost, total capital
requirement and consumable costs. The cost-effectiveness figures
in the report are based on data from different geographic regions
and represent a variety of averaging times. The EPA believes the
data are appropriate to use with respect to the EPA presumptive
NOx RACT 30-day rolling average or to a daily average.
As described in tables 1-4 and 1-5 of the EPA/NESCAUM
report, the combustion-modification technologies available to
meet EPA's presumptive NOx RACT levels show a range of cost
effectiveness of about $160 to $5100 per ton; and the post-
combustion technologies, excluding selective catalytic reduction,
show a range of about $320 to $5200 per ton. These are national
estimates based on constant 1991 (1st quarter) dollars. Some
States may need to make regional adjustments to this range to
reflect prevailing installation and operating labor costs which
are higher or lower than the national average. The data indicate
that some coal burning wall-fired boilers can meet EPA's
presumptive NOx RACT levels by application of low NOx burners at
a cost effectiveness as low as $160 per ton. The data also
indicate that certain tangentially-fired utility boilers may
approach a cost-effectiveness level of $1300 per ton in order to
meet the EPA presumptive NOx RACT levels. Application of
selective catalytic reduction to utility boilers does not appear
necessary in order to meet the EPA presumptive NOx RACT levels.
In determining the NOx RACT comparable cost-effectiveness
level, EPA believes that it is appropriate to focus on the range
of cost effectiveness. The range is appropriate due to the
variability of the actual cost effectiveness that is expected
from unit to unit. Therefore, NOx technologies with a cost-
effectiveness range that overlaps the $160 to $1300 range should,
at a minimum, be considered by States in the development of their
NOx RACT requirements.
In some cases, States will need to consider a broader cost-
effectiveness range. For example, where States adopt NOx RACT
requirements that are more stringent than the EPA's presumptive
RACT, the associated control technologies may result in higher
cost-effectiveness figures and, thus, States should expect to
apply a broader cost-effectiveness range. In addition, since the
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EPA's presumptive RACT levels are expected to be met by a
majority of (but not all) sources, States should expect some
sources to experience higher cost-effectiveness levels in order
to meet the NOx RACT requirements.
While cost effectiveness, as described above, is an
important consideration, it must be noted that other factors
should be integrated into a RACT analysis. For example, emission
reductions and environmental impact should be considered.
Regarding emission reductions, a comparison of uncontrolled NOx
emission levels (from the EPA/NESCAUM report) with EPA's
presumptive RACT levels indicates that the utility boilers are
expected to achieve emission reductions of about 30 to 50
percent. If control technologies in the $160 to $1300 range are
inadequate to achieve emission reductions in the 30 to 50 percent
range, then the State should consider alternate technologies
which achieve those reduction levels. For example, if a RACT
analysis indicates that a cost effectiveness of $2000 per ton is
necessary to achieve emission reductions in the 30 to 50 percent
range, the State may need to adopt that requirement in order to
achieve comparable emission reductions, consistent with EPA's
guidance.
The environmental impact of various control technologies
should be included in the RACT determination in some cases. For
example, sources that operate intermittently, but whose peak
operating times coincide with the peak ozone periods, should be
considered separately from sources with relatively constant year-
round emissions. In addition, where an otherwise acceptable
control technology might significantly increase carbon monoxide
(CO) emissions in a CO nonattainment area, the State should
consider alternate technologies.
Questions concerning this memorandum can be addressed to
John Silvasi at (919) 541-5666; questions on specific
technologies and costs can be addressed to Bill Neuffer at (919)
541-5435.
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96
D-9
Nitrogen Oxides Questions from the Ohio EPA
(3-30-94)
This memorandum addresses the NOx reasonably available
control technology (RACT) issues raised in a November 30, 1993
memorandum from Richard Schleyer, EPA Region V, to John Silvasi.
The issues include the following: Seasonal NOx RACT rules; 30 day
rolling average; NOx emission trading; Fuel switching; and NOx
compliance schedules.
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3-30-94
MEMORANDUM
SUBJECT: Nitrogen Oxides (NOx) Questions from Ohio EPA
FROM: Tom Helms, Chief
Ozone/Carbon Monoxide Programs Branch
TO: Air Enforcement Branch
Region V
This memorandum addresses the NOx reasonably available
control technology (RACT) issues raised in a November 30, 1993
memorandum from Richard Schleyer, EPA Region V, to John Silvasi,
Office of Air Quality Planning and Standards. These issues were
discussed and resolved by the NOx Work Group.
Question 1:
Can the NOx RACT rules be made applicable only during
the summer months since ozone is a summer problem? If not,
why not?
Answer 1:
The EPA's RACT guidance for volatile organic compounds
(VOC) states that seasonal controls are generally not
allowed (EPA clarification to Appendix D of the November 24,
1987 Federal Register, "Issues Relating to VOC Regulations
Cutpoints, Deficiencies, and Deviations," revised 1-1-90).
As stated in the NOx Supplement to the General Preamble (57
FR 55625, November 25, 1992), the VOC RACT guidance is
generally applicable to NOx RACT. Thus, the limitation on
seasonal controls also applies to NOx RACT.
The EPA's definition of RACT is "The lowest emission
limitation that a particular source is capable of meeting by
the application of control technology that is reasonably
available considering technological and economic
feasibility" (44 FR 53762, September 17, 1979). Thus, RACT
is not generally a function of season or other temporal
factors. There are limited exceptions, however, in the VOC
and NOx programs where seasonal controls are allowed. For
example, EPA has developed RACT guidance for seasonal
controls concerning cutback asphalt (VOC) and fuel switching
(NOx).
Question 2:
Comments have been received that a 30-day rolling
average should be allowed using stack tests. The Ohio EPA
is not aware of any method other than use of a continuous
emissions monitor (CEM) where a 30-day rolling average is
possible. Is there any other method possible?
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Answer 2:
This issue should be addressed in the context of the
enhanced compliance monitoring rulemaking, which is in
process.
Question 3:
If a source is subject to a federally enforceable
permit to install, which requires best available control
technology (BACT), would the facility have to submit a RACT
study or meet any of the other requirements contained in
Ohio's NOx RACT rules?
Answer 3:
RACT requirements can, in some cases, be more stringent
than the lowest achievable emission rates (LAER) or BACT
(see February 28, 1990 memorandum from John Calcagni to
Regional Offices). Therefore, where a source has already
installed BACT or LAER, the State would still need to
complete an analysis to show that BACT or LAER is at least
as stringent as RACT in that case. If RACT is more
stringent, then the RACT requirements would apply.
Question 4:
Is one-source trading allowed? For example, if a
source uses selective non-catalytic reduction to control
NOx, could the source simply turn-on and turn-off this
control device, as necessary, to comply with NOx RACT?
Answer 4:
Once a State sets a NOx RACT emission rate limit for a
source category, individual sources are generally free to
meet that limit in a variety of ways. Where a State adopts
a NOx RACT emission rate limit with a long averaging time,
such as 30 days, a source with a continuous emission monitor
could conceivably turn-on and turn-off very stringent
controls on, for example, alternate days and still meet the
RACT limit. States should, however, avoid adopting RACT
rules which could result in sources maximizing their
emissions on high ozone potential days, thus jeopardizing
attainment.
Questions 5 & 9:
Will partial switching to natural gas (co-firing gas
and coal) need a SIP revision? Are site-specific SIP
revisions needed if a source is complying with NOx RACT
using fuel switching?
Answer 5:
Individual sources that switch to natural gas do not
need source-specific SIP revisions as long as the statewide
NOx RACT rules allow such switching and are consistent with
EPA guidance (July 30, 1993 memorandum from Michael H.
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Shapiro to Regional Offices on fuel switching to meet the
NOx RACT requirements). If there is no such statewide rule,
then a SIP revision would be needed to meet the NOx RACT
requirements.
Question 6:
Can major NOx sources that only operate outside the
ozone season be exempt from NOx RACT?
Answer 6:
The RACT requirement applies to major stationary
sources, considering potential annual emissions. However,
major NOx sources which are prohibited from operating during
the ozone season might qualify for an exemption from the NOx
requirements under section 182(f) of the amended Act. The
EPA would consider a petition requesting such an exemption.
Question 7:
Will compliance schedule changes up to April 1, 1996 be
allowed without a SIP revision?
Answer 7:
Sources that do not meet milestones contained in the
State's NOx RACT rule would be subject to enforcement
actions.
Question 8:
Is switching from (1) coal to oil or (2) oil to natural
gas allowed under the fuel switching program? If yes, what
limits would apply in either case?
Answer 8:
The EPA's guidance on fuel switching to meet NOx RACT
(referenced in answer 5) is not limited to coal to natural
gas switches. That guidance would need to be applied in
each case to determine the applicable emission limits.
Question 10:
Are site-specific SIP revisions needed if a source is
complying with NOx RACT using an emissions trading program?
Answer 10:
Individual sources that comply with NOx RACT through an
emissions trading program do not need source-specific SIP
revisions as long as the statewide NOx RACT rules provide
for such a trading program and are consistent with EPA
guidance (reference forthcoming NOx trading guidance memo).
If there is no such statewide rule, then a SIP revision
would be needed to meet the NOx RACT requirements.
cc: Air Branch Chiefs
NOx Work Group
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100
D-10
Section 182 (f) NOx Exemptions-Revised Process and Criteria
(5-27-94)
This memorandum presents updated guidance on how EPA reviews
and processes requests for exemption from the NOx RACT
requirements under section 182(f) of the Clean Air Act (Act). It
also revises certain guidance previously issued concerning NOx
exemptions for areas outside the ozone transport region that have
air quality monitoring data showing attainment.
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May 27, 1994
MEMORANDUM
SUBJECT: Section 182(f) Nitrogen Oxides (NOX) Exemptions—
Revised Process and Criteria
FROM: John S. Seitz, Director
Office of Air Quality Planning and Standards (MD-10)
TO: Director, Air, Pesticides and Toxics Management
Division, Regions I and IV
Director, Air & Waste Management Division, Region II
Director, Air, Radiation and Toxics Division, Region
III
Director, Air & Radiation Division, Region V
Director, Air, Pesticides and Toxics Division, Region
VI
Director, Air & Toxics Division,
Regions VII, VIII, IX, and X
This memorandum revises the process the Environmental
Protection Agency (EPA) currently intends to follow for granting
exemptions from control requirements for NOX under section 182(f)
of the Clean Air Act (Act) .' It also revises certain guidance
previously issued concerning NOX exemptions for areas outside the
ozone transport region that have air quality monitoring data
showing attainment.2
The guidance in this memorandum applies to marginal and
above ozone nonattainment areas because the section 182(f)
exemption is directed at major NOX stationary sources only in
'"Guideline for Determining the Applicability of Nitrogen
Oxide Requirements under Section 182(f)," from John S. Seitz,
Director, Office of Air Quality Planning and Standards, to the
Regional Division Directors, December 16, 1993, Chapter 2,
Administrative Procedures.
2"State Implementation Plan (SIP) Requirements for Areas
Submitting Requests for Redesignation to Attainment of the Ozone
and Carbon Monoxide (CO) National Ambient Air Quality Standards
(NAAQS) on or after November 15, 1992," from Michael H. Shapiro,
Acting Assistant Administrator for Air and Radiation, to the
Regional Division Directors, September 17, 1993 [NOX reasonably
available control technology (RACT) discussion on pages 4-5] and
December 1993 guideline at section 4.4.
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marginal and above ozone nonattainment areas. The guidance does
not address nonclassifiable ozone nonattainment areas (i.e.,
transitional, submarginal, or incomplete/no data areas).
However, the EPA's conformity rules*4 also reference the section
182(f) exemption process as a means for exempting affected areas
from NOX conformity requirements.5 Moreover, under these rules,
conformity applies in all nonattainment and maintenance areas,
including the nonclassifiable nonattainment areas. Therefore,
corresponding guidance is needed for the application of the
section 182(f) NOX exemption referenced in the conformity rules
in these nonclassifiable areas. The guidance document entitled
"Conformity; General Preamble for Exemption from Nitrogen Oxides
Provisions," to be published in the Federal Register, addresses
how EPA generally intends to act on requests for NOX conformity
exemption determinations for those areas, and should be consulted
for those purposes along with this guidance.
Ozone nonattainment areas that are granted areawide section
182(f) exemptions under the approach described in this memorandum
will also be exempt from the NOX conformity requirements.
However, since the conformity requirements apply on an areawide
basis, a section 182(f) exemption for an individual source (or
group of sources) within the nonattainment or maintenance area
would not provide a sufficient basis to exempt the entire
nonattainment or maintenance area from the NOX conformity
requirements.
Section 182(f) requires States to apply the same
requirements to major stationary sources of NOX as are applied to
major stationary sources of volatile organic compounds. The
3"Criteria and Procedures for Determining Conformity to
State or Federal Implementation Plans of Transportation Plans,
Programs, and Projects Funded or Approved under Title 23 U.S.C.
of the Federal Transit Act," November 24, 1993 (58 FR 62188).
""Determining Conformity of General Federal Actions to State
or Federal Implementation Plans; Final Rule," November 30, 1993
(58 FR 63214).
5The section 182(f) exemption is explicitly referred to and
is described in similar language in 40 CFR 51.394(b)(3)(i), the
"Applicability" section of the transportation conformity rule,
and in the preamble (see 58 FR 62197, November 24, 1993). The
language is repeated in the provisions of the rule regarding the
motor vehicle emissions budget test [section 51.428(a)(1)(ii)]
and the "build/no-build" test [sections 51.436(e), 51.438(e) ],
although section 182(f) of the Act is not specifically mentioned.
In the general conformity rule, the section 182(f) NOx exemption
is referred to in section 51.852 (definition of "Precursors of a
criteria pollutant") and is discussed in the preamble (see 58 FR
63240, November 30, 1993).
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requirements are RACT and new source review (NSR). The NOX RACT
is required in ozone nonattainment areas classified as moderate
and above, as well as in all areas within an ozone transport
region. The NSR rules are required in ozone nonattainment areas
classified as marginal and above, as well as all areas within an
ozone transport region. Section 182(f) also specifies
circumstances under which the new NOX requirements would be
limited or would not apply.
Under section 182(f)(1)(A), an exemption from the NOX
requirements may be granted for nonattainment areas outside an
ozone transport region if EPA determines that "additional
reductions of [NOx] would not contribute to attainment" of the
ozone NAAQS in those areas. The EPA has indicated that in cases
where a nonattainment area is demonstrating attainment with 3
consecutive years of air quality monitoring data, without having
implemented the section 182(f) NOX provisions, it is clear that
this test is met since "additional reductions of [NOx] would not
contribute to attainment" of the NAAQS in that area. Under this
revised guidance, a State may submit a petition for a section
182(f) exemption based on air quality monitoring data showing
attainment of the ozone NAAQS without also having to submit a
redesignation request or a maintenance plan with that
petition.67 The EPA's approval of the exemption, if warranted,
would be granted on a contingent basis (i.e., the exemption would
last for only as long as the area's monitoring data continue to
demonstrate attainment).
If it is subsequently determined by EPA that the area has
violated the standard, the section 182(f) exemption, as of the
date of the determination, would no longer apply. The EPA would
notify the State that the exemption no longer applies, and would
also provide notice to the public in the Federal Register. A
determination that the NOX exemption no longer applies would mean
that the area would thereafter have to address any NOX NSR or NOX
RACT requirements that may be applicable under section 182(f).
Similarly, while existing transportation plans, transportation
6For purposes of the NOx exemption test in section
182(f)(l)(A) for areas outside an ozone transport region, EPA is
interpreting the term "contribute to attainment" to mean that the
State (or petitioner) need only show whether additional
reductions of NOx would contribute to attainment of the ozone
NAAQS, and not whether such reductions would contribute to
attainment and maintenance.
7The section 182(f) exemption does not affect EPA's
requirements for maintenance plans; the maintenance plan required
for redesignation must still address NOX in accordance with EPA
guidance.
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improvement plans and past conformity determinations would not be
affected by a determination that the exemption no longer applies,
new conformity determinations would have to observe the NOX
requirements of the conformity rule. The State must continue to
operate an appropriate air quality monitoring network, in
accordance with 40 CFR part 58, to verify the attainment status
of the area. The air quality data relied on for the above
determinations must be consistent with 40 CFR part 58
requirements and other relevant EPA guidance and recorded in
EPA's Aerometric Information Retrieval System (AIRS).
Section 182(f) contains very few details regarding the
administrative procedure for acting on NOX exemption requests.
The absence of specific guidelines by Congress leaves EPA with
discretion to establish reasonable procedures, consistent with
the requirements of the Administrative Procedure Act (APA).
The EPA believes that section 182(f) sets up two separate
procedures by which the Agency may act on NOX exemption requests.
Section 182(f)(l) and (2) direct that action on NOX exemption
determination requests should take place "when [EPA] approves a
plan or plan revision." This language appears to contemplate
that exemption requests submitted under these paragraphs are
limited to States, since States are the entities authorized under
the Act to submit plans or plan revisions. By contrast, section
182(f)(3) provides that "person[s]"8 may petition for a NOX
determination "at any time" after the ozone precursor study
required under section 185B of the Act is finalized,9 and gives
EPA a limit of 6 months after filing to grant or deny such
petitions. Although section 182(f)(3) references 182(f)(l),
there are certain key differences in the language. First,
individuals may submit petitions under paragraph (3) "at any
time" (i.e., even when there is no plan revision from the State
pending at EPA). Second, the specific timeframe for EPA action
established in paragraph (3) is substantially shorter than the
timeframe usually required for States to develop and for EPA to
take action on revisions to a SIP. These differences strongly
suggest that Congress intended the process for acting on personal
petitions to be distinct—and more expeditious—from the plan-
revision process intended under paragraph (1). Thus, EPA
believes that paragraph (3)'s reference to paragraph (1)
encompasses only the substantive tests in paragraph (1) [and, by
extension, paragraph (2)], not the requirement in paragraph (1)
for EPA to grant exemptions only when acting on plan revisions.
"Section 302(e) of the Act defines the term "person" to
include States.
9The final section 185B report was issued July 30, 1993.
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The requirements of the APA apply with respect to the type
of notice which must be provided regarding EPA action on NOX
exemption determinations. Notice-and-comment rulemaking is
required by the APA when EPA action involves not just factual,
but also policy and legal considerations that will apply as a
general matter and, thus, is legislative in nature. Conversely,
when EPA action can properly be described as party specific in
nature, involving consideration of primarily factual evidence,
notice-and-comment rulemaking is not required by the APA. In
such a case, the EPA action could consist of the issuance of an
order [see 5 U.S.C. sections 551(4)-(7) and 553]. Given these
requirements of the APA, EPA believes that under either of the
procedures established in section 182(f), where the request is
for an entire area to be exempted from the NOX requirements, the
EPA must go through notice-and-comment rulemaking to grant or
deny the petition. Where a petition is submitted for an
exemption determination relating to an individual source (or
group of sources) under subsection 182(f)(3), EPA may grant or
deny the petition through an order transmitted by letter to the
affected source (or sources). The EPA will also provide the
public with notice in the Federal Register of the receipt and
availability of the petition, as well as of the EPA's final
determination.
Attachment I of this memorandum is the step-by-step
administrative procedure for processing areawide petitions.
Attachment II is the procedure for processing petitions relating
to an individual source (or group of sources).
Section 182(f)(3) requires that EPA grant or deny a
petition, whether areawide or source specific, within 6 months
after its filing. Where the rulemaking process is followed (for
areawide petitions), EPA is aware that the 6-month requirement
may be infeasible in some cases. However, courts have ruled that
even in instances, such as the one presented here, where a
prescribed timeframe for EPA action apparently conflicts with the
requirement to provide the public with adequate opportunity for
notice and comment, the notice requirement must be met.
Therefore, EPA will process areawide exemption requests by
rulemaking as expeditiously as practicable, with the intent of
meeting the 6-month deadline.
As noted earlier, petitions submitted under section
182 (f)(3) are not required to be submitted as SIP revisions.
Consequently, the State is not required under the Act to hold a
public hearing in order to petition for an areawide NOX exemption
determination [see section 110(a)(l) and (2)]. For similar
reasons, if the State is submitting an areawide petition under
subsection 182(f)(3), it is unnecessary to have the Governor
submit the petition. However, because of the need for
consistency with the AIRS data and the requirements of 40 CFR
-------
part 58, EPA believes that, particularly in cases where the NOX
exemption request (including a request for exemption from the NOX
requirements of the conformity rules) is based on monitoring
data, if such data are contained in a petition submitted by a
person other than the State, the petition should be coordinated
with the State air agency.
The Federal Register notice of EPA approval or disapproval
of a State's petition must be signed by the Administrator. This
is not a SIP action or a redesignation action. Consequently,
this action is not delegated and must undergo Headquarters
review. If some or all types of petition actions become
delegated, notification will be provided.
Where there is a conflict, this guidance supersedes
guidance contained in EPA's September 17, 1993 memorandum and in
sections 2.2 and 4.4 of EPA's December 16, 1993 document. Please
contact Doug Grano (919) 541-3292 or Kimber Scavo (919) 541-3354
regarding any questions.
Attachments
cc: Tom Helms
Steve Hitte
Robert Kellam
Phil Lorang
Rich Ossias
Joe Tikvart
Lydia Wegman
-------
Attachment I
(Rulemaking for Areawide Petition)1
(1) The petition is sent to the appropriate Regional Offices
(RO's) and States by the petitioner.
(2) The RO sends copies of the petition to Headquarters (HQ)
Offices for technical and legal review. These offices are:
Ozone/Carbon Monoxide Programs Branch, AQMD (Doug Grano);
Source Receptor Analysis Branch, TSD (Ned Meyer); Office of
Mobile Sources (Kathryn Sargeant); and Office of General
Counsel (Mike Prosper). (The petition should be sent
immediately upon receipt.)
(3) The RO evaluates the demonstration and makes the initial
determination as to whether the petition should be granted
or denied along with the supporting rationale. The RO
should consult with the above HQ Offices and affected
States.
(4) The RO prepares a Federal Register (FR) notice for the
Administrator's signature that proposes to grant or deny the
petition. A notice that proposes to grant an exemption on a
contingent basis (for areas outside the ozone transport
region that have air quality monitoring data showing
attainment) must also propose that the exemption would no
longer apply if EPA subsequently determines that a violation
of the ozone standard has occurred. That proposal must
specify that the NOX requirements of the conformity rules
would apply to new conformity determinations, and the amount
of time the State would have to submit any applicable
section 182 (f) NOX NSR and/or RACT rules in the event that
EPA determines at some future time that a violation
occurred.
The evaluation under step 3 above must be included in either
the FR notice or a technical support document that is
included in the docket. (The RO should prepare and complete
the FR proposal within 2 months after receipt, taking into
account any HQ comments on the petition or the RO
evaluation.*
'This process assumes no delegation to the Regional
Administrator.
Petitions that are based on an area having data indicating
that it has already attained the ozone standard should generally
be processed in less time.
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(5) The FR proposal is sent to HQ reviewers for concurrence. (HQ
should finish the review within 1 month after receipt.)
(6) After any revision and concurrence by HQ reviewers, the FR
proposal is sent to the Administrator for signature and is
then published. (There should be at least 1 month for a
formal comment period after FR publication.)
(7) The RO prepares a FR notice of final rulemaking that
addresses comments received and takes final action to grant
(fully or on a contingent basis) or to deny the petition.
The RO sends the notice to the HQ reviewers noted above
under Step 2. (HQ should finish the review within 1 month
after receipt.)
(8) After any revision and concurrence by HQ reviewers, the FR
final notice is sent to the Administrator for signature and
is then published.
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Attachment II1
[Letter of Approval/Denial for Individual Source (or Group of
Sources) Petition]
(1) The petition is sent to the affected States and RO's by the
petitioner.
(2) The RO prepares a FR notice of availability and sends it
directly to the FR after Regional Administrator signature.
This notice does not indicate EPA's intended action. The
EPA notice should solicit comments. However, because the
action is not a rulemaking, there is no obligation on EPA's
part to respond to the comments when taking final action.
The EPA provides affected States a 3-month period to make a
recommendation to EPA.
(3) The RO sends a copy of the petition to the HQ Offices listed
in Attachment I, Step 2.
(4) The RO makes the initial determination as to whether the
petition should be granted or denied in consultation with
affected States. The determination is incorporated by the
RO into a letter for signature of the Administrator, along
with the supporting rationale.
(5) The draft letter is sent to HQ reviewers for concurrence.
(6) After concurrence by HQ reviewers, the final letter is
prepared by the RO and sent to the Administrator for
signature ("cc" to the affected States).
(7) The RO prepares a second FR notice that includes the letter
signed by the Administrator to the petitioner and sends the
notice directly to the FR after Regional Administrator
signature.
'This process assumes no delegation to the Regional
Administrator.
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110
D-ll
Conformity: General Preamble for Exemption from
Nitrogen Oxides Provisions
(6-17-94 FR; 59 FR 31238)
This General Preamble clarifies how EPA believes that
nonclassifiable (i.e., submarginal, transitional, and
incomplete/no data) ozone nonattainment areas which are outside
the Northeast ozone transport region and have ambient monitoring
data demonstrating attainment of the national ambient air guality
standard for ozone may be exempted from the conformity rules7
nitrogen oxides (NOx) requirements. This notice also references
a recent memorandum which states EPA's preliminary interpretation
for such ozone nonattainment areas which are classified as
marginal or above.
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31238
Federal Register / Vol. 59, No. 116 /Friday, June 17, 1994 / Notices
ENVIRONMENTAL PROTECTION
AGENCY
[FRL-5000-3]
Agency Information Collection
Activities Under OMB Review
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Notice.
SUMMARY: In compliance with the
Paperwork Reduction Act (44 U.S.C.
3501 et seq.), this notice announces that
the Information Collection Request (ICR)
abstracted below has been forwarded to
the Office of Management and Budget
(OMB) for review and comment. The
ICR describes the nature of the
information collection and its expected
cost and burden; where appropriate, it
includes the actual data collection
instrument.
DATES: Comments must be submitted on
or before July 18.1994.
FOR FURTHER INFORMATION CONTACT: For
further information, or a copy of this
ICR contact Sandy Farmer at EPA, (202)
260-2740.
SUPPLEMENTARY INFORMATION:
-Office of Solid Waste and Emergency
Response
Title: Collection of Economic and
Regulatory Support Data Under RCRA
(ICR No. 1641.01). This ICR requests
approval for a new collection.
Abstract: EPA's Office of Solid Waste
(OSW) is requesting approval for a
generic clearance to collect economic
and regulatory impact data through
surveys, interviews, or focus group
meetings with industry or other parties
in support of the Resource Conservation
and Recovery Act (RCRA) rulemaking
actions.
RCRA, as amended by the Hazardous
and Solid Waste Amendments, requires
EPA to establish a national regulatory
program to ensure that hazardous waste
is managed in a manner protective of
human health and the environment.
EPA is authorized under sections 2002
and 3007 of RCRA to collect information
from industry and other parties when
necessary to carry out its regulator}'
responsibilities.
The information collected will be
used to assess the costs and benefits of
various potential regulatory and
nonregulatory actions.
The first collection to be administered
under the generic clearance, the
Hazardous Waste Identification Rule
(HW1R) Expert Elicitations, is included
in this ICR. Information will be
collected through interviews (expert
dictations) with hazardous and
industrial solid waste experts to support
development of alternative approaches
for hazardous waste identification. The
Agency will conduct two sets of expert
elicitations, one for each HWIR
regulatory option: Contaminated Soil
and Sediment Media; and Contaminated
Debris.
Burden Statement: The public
reporting burden for this generic
collection is estimated to-average 3
hours per response and the burden for
the HWIR Expert Elicitations collection
ranges from 15 minutes to 1.5 hours per
respondent. These estimates include all
aspects of the information collection
including the time for reviewing
instructions, searching existing data
sources, gathering the data needed, and
completing and reviewing the collection
of information.
Respondents: Hazardous waste
generators, scientists, industry experts,
and treatment, storage and disposal
facilities.
Estimated Number of Respondents:
3.000.
Estimated Number of Responses per
Respondent: 1.4.
Estimated Total Annual Burden on
Respondents: 12,780 hours.
Frequency of Collection: On Occasion.
Send comments regarding the burden
estimate, or any other aspect of this
collection of information, including
suggestions for reducing the burden, to:
Sandy Fanner, U.S. Environmental
Protection Agency, Information Policy
Branch (2136), 401 M Street. SW.,
Washington, DC 20460.
and
Jonathan Giedhill, Office of
Management and Budget, Office of
Information and Regulatory Affairs.
725 17th Street, NW., Washington. DC
20503.
Dated: June 13.1994.
Paul Lepsley,
Director, Regulatory Management Du.ixion.
[FR Doc. 94-14819 Filed 6-16-94. 8 45 am]
BILLING COO£ 6S-SC-50-F „
[FRL-4998-6]
Conformity; General Preamble for
Exemption From Nitrogen Oxides
Provisions
AGENCY: Environmental Protection
Agency (EPA).
ACTION: General preamble for future
proposed rulemakings.
SUMMARY: This General Preamble
clarifies how EPA believes that
nonclassifiable (i.e.. submarginal.
transitional, and incomplete/no data)
ozone ncmattainment areas which are
outside the Northeast ozone transport
region and have ambient monitoring
data demonstrating attainment of the
national ambient air quality standard for
ozone may be exempted from the
conformity rules' nitrogen oxides (NOJ
requirements. This notice also
references a recent memorandum which
states EPA's preliminary interpretation
for such ozone nonattainment areas
which are classified as marginal or
above.
Clarification of EPA policy for areas
with monitoring data which
demonstrates attainment is particularly
important because many areas already
have such data and appear to qualify for
exemption from the conformity NO.
requirements.
In order to avoid repetition, this
General Preamble describes guidance on
NOx exemptions with respect to the
transportation conformity rule.
However, this guidance for
transportation conformity is intended to
elso apply with respect to general
conformity.
This General Preamble explains EPA's
policy generally for future notice-and-
comment rulemakings taking action on
requests for NOx exemptions for
specific areas. It contains EPA's
preliminary interpretations of relevant
provisions of the Clean Air Act and the
conformity rules. The interpretations
contained herein are not binding as a
matter of law until final rulemaking
action is taken on each specific area.
Opportunity for public comment on
NOx exemption determinations made by
EPA will be provided separately for
each area during these individual
rulemakings.
FOR FURTHER INFORMATION CONTACT: For
issues related to transportation
conformity, Kathryn Sargeant, Emission
Control Strategies Branch, Emission
Planning and Strategies Division. U.S.
Environmental Protection Agency, 2565
Plymouth Road, Ann Arbor, MI 48105.
(313) 668-4441. For issues related to
redesignation, David Cole, (919/ 541-
5565. and for issues related to general
conformity and NOx RACT and NSR,
Doug Grano, (919) 541-3292, Ozone/CO
Programs Branch (MD-15), Air Quality
Management Division, U.S.
Environmental Protection Agency,
Research Triangle Park, North Carolina
27711.
SUPPLEMENTARY INFORMATION:
I. Background
A. Transportation Conformity Rule
The transportation conformity final
rule, entitled "Criteria and Procedures
for Determining Conformity to State or
Federal Implementation Plans of
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Federal Register / Vol. 59, No. 116 / Friday, June 17, 1994 / Notices 31239
Transportation Plans, Programs, and
Projects Funded or Approved Under
title 23 U.S.C. or the Federal Transit
Act," was published in the Federal
Register on November 24, 1993 (58 FR
62188). This action was required under
section 176(c)(4) of the Clean Air Act, as
amended in 1990.
Conformity to an implementation
plan is defined in the Clean Air Act as
conformity to an implementation plan's
purpose of eliminating or reducing the
severity and number of violations of the
national ambient air quality standards
and achieving expeditious attainment of
such standards. In addition, Federal
activities may not cause or contribute to
new violations of air quality standards,
exacerbate existing violations, or
interfere with timely attainment or
required interim emission reductions
towards attainment. The transportation
conformity final rule establishes the
process by which the Federal Highway
Administration and the Federal Transit
Administration of the United States
Department of Transportation and
metropolitan planning organizations
determine the conformity of highway
and transit projects. Under the rule,
conformity applies in nonattainment
and maintenance areas.
The transportation conformity rule
requires ozone nonattainment and
maintenance areas to perform a regional
emissions analysis of motor vehicle
NOx emissions in order to determine
the conformity of transportation plans
and programs. This analysis must
demonstrate that the NO* emissions
which would result from the
transportation system if the proposed
transportation plan and program were
implemented are within the total
allowable level of NOX emissions from
highway and transit motor vehicles
("motor vehicle emissions budget"), as
identified in a submitted or approved
attainment demonstration or
maintenance plan.
Until an attainment demonstration or
(for nonclassifiable areas) a maintenance
plan is approved by EPA, the regional
emissions analysis of the transportation
system must also satisfy the "build/no-
build test." That is, the analysis must
demonstrate that emissions from the
transportation system if the proposed
transportation plan and program were
implemented would be less than the
emissions from the transportation
system if only the previously applicable
transportation plan and program were
implemented. Furthermore, the regional
emissions analysis must show that
emissions from the transportation
system if the transportation plan and
program were implemented would be
lower than 1990 levels by any nonzero
amount.
The transportation conformity rule as
currently written provides for an
exemption from these requirements
with respect to NO, if the Administrator
determines under section 182(f) of the
Clean Air Act that additional reductions
of NO, would not contribute to
attainment. This exemption is explicitly
referred to and is described in similar
language in § 51.394(b)(3)(i) (the
"Applicability" section of the rule) and
in the preamble (58 FR 62197,
November 24,1993). The language is
repeated in the provisions of the rule
regarding the motor vehicle emissions
budget test (§51.428(a)(l)(ii)) and the
"build/no-build" test (§§ 51.436(e),
51.438(e)), although Clean Air Act
section 182(0 is not specifically
mentioned.
Section 182(Q of the Clean Air Act
contains requirements for—and in some
cases, exemptions for—major stationary
NO, sources in marginal and above
ozone nonattainment areas and in an
ozone transport region. EPA guidance
for application of section 182(f) in these
areas is briefly described and referenced
in the next section of this preamble.
Because the transportation conformity
rule covers all nonattainment areas—
including nonclassifiable ozone
nonattainment areas (i.e., submarginal,
transitional, incomplete/no data areas)
that are not necessarily covered under
section 182(0—corresponding guidance
is needed for applying in these
nonclassifiable ozone nonattainment
areas the section 182(0 NO, exemption
referenced in the transportation
conformity rule. This guidance is
described below (section II, "EPA
Policy") and is consistent with the
existing guidance that applies to the
marginal and above areas outside an
ozone transport region. The substantive
test for a NO, exemption is the same in
both sets of areas, but in nonclassifiable
ozone nonattainment areas the effect of
a NO, exemption is limited solely to the
issue of whether such areas may be
exempted from meeting the NO,
requirements of the transportation
conformity rule.
B. General Conformity
On November 30,1993 (58 FR 63214),
EPA published the general conformity
final rule, entitled "Determining
Conformity of General Federal Actions
to State or Federal Implementation
Plans." This action was required under
section 176(c)(4) of the Clean Air Act, as
amended in 1990.
Like the transportation conformity
rule, the genera) conformity rule
exempts an area from considering NO,
emissions if the area has been exempted
under section 182(0 of the Clean Air Act
(see definition of "precursors of a
criteria pollutant," 58 FR 63248).
In order to avoid repetition, this
General Preamble describes guidance en
NO, exemptions with respect to the
transportation conformity rule
However, this guidance for
transportation conformity is intended fo
also apply with respect to genera)
conformity.
C. Section I82(f) of the Clean Air Act
Section 182(0 of the Clean Air Act
requires states to apply the reasonably
available control technology (RACT)
and new source review (NSR)
requirements that apply to major
stationary sources of volatile organic
compounds to major stationary sources
of NO, as well. NOX RACT is required
in moderate and above ozone areas, es
well as in all areas within an ozone
transport region. NO* NSR regulations
are required in marginal and above
ozone areas, as well as in all areas
within an ozone transport region.
Clean Air Act section 182(0(1){A)
states that, for nonattainmenl areas noJ
within an ozone transport region (as
established under Clean Air Act section
184), these NOX requirements shall not
apply if the Administrator determines
that additional reductions of NO>
would not contribute to attainment of
the national ambient air quality
standard (NAAQS) for ozone in the ares
Furthermore, for areas within an ozone
transport region, section 182(0(1)(B)
states that these stationary source K'OX
requirements shall not apply if
additional NOx reductions xvould no!
produce net ozone air quality benefits in
the region.
EPA issued limited guidance on
section 182(f) exemptions in a
September 17, 1993 memo from Mich&el
H. Shapiro, Acting Assistant
Administrator for Air and Radiation to
the Regional Air Division Directors
entitled, "State Implementation Plan
(SIP) Requirements for Areas Submitting
Requests for Redesignation to
Attainment of the Ozone and Carbon
Monoxide (CO) National Ambient Air
Quality Standards (NAAQS) on or after
November 15,1992." EPA issued more
extensive guidance in a December 1993
document entitled, "Guideline for
Determining the Applicability of
Nitrogen Oxide Requirements under
section 182(0-" Most recently, EPA h&s
clarified and, in part, revised its
guidance in a May 27.1994
memorandum from John S. Seitz
Director of the Office of Air Quality
Planning and Standards, to Regional Air
Division Directors, "Section 182(0 NCK
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31240
Federal Register / Vol. 59, No. 116 / Friday, June 17. 1994 / Notices
Exemptions—Revised Process and
Criteria." All of these guidance
documents are available by request from
the contacts listed above.
Taken together, these guidance
documents state that if an area (not
within an ozone transport region) has
attained the ozone standard, as
demonstrated by adequate monitoring
data consistent with EPA guidance, it is
clear that additional NOx reductions
would not contribute to attainment.
Therefore, such an area would meet the
test under section 182(f)(l)(A) for an
exemption from NOX NSR and RACT
requirements.
II. EPA Policy
A. Transportation Conformity and
Section 182(f) Exemptions
The transportation conformity rule
states that its NOx provisions do not
apply when the Administrator has
determined under section 182(f) of the
Clean Air Act that "additional
reductions of NOx would not contribute
to attainment." Although two other
passages of the transportation
conformity rule use this language
(which is borrowed from section
182(f)(lHA)'s test for areas outside an
ozone transport region) without
specifically referring to section 182(f).
EPA believes there is no appropriate
basis to interpret this identical language
differently under the transportation
conformity rule than under the Clean
Air Act Consequently, EPA believes
this common language should be
interpreted similarly for purposes of
both section 182{f) and conformity NOx
exemptions. Therefore, EPA is
providing guidance which would
exempt nonclassifiable ozone
nonattainment areas outside an ozone
transport region from the conformity
rule's NOx provisions on the same
substantive basis as the applicable
section 182(f) test.1
1 As explained in footnote 6 of the May 27.1994
memorandum from John Seitz. referenced above, for
purposes of the NOx exemption test. EPA is
interpreting the term "contribute to attainment" to
mean that the State (or petitioner) need only show
whether addition*! NOx reductions would
contribute to attainment, not whether such
reductions would contribute to attainment and
maintenance. EPA believes that Congress could
reasonably have believed it appropriate to require
that States impose reasonably available control
technology (RACT) and new source review (NSR)
requirements on NOx sources for areas in
nonattainment. bat that the States could be left to
decide for themselves whether to impose these NOx
controls or other measures for maintenance
purposes, even if these controls could "contribute"
to maintenance. EPA believes this rationale also
applies in the conformity context where EPA
believes it U reasonable to allow States that have
aitamed the NAAQS to decide for themselves how
host to ensure maintenance ol the standard. And.
as explained below. EPA has conditioned the
The transportation conformity rule
applies to all nonattainment and
maintenance areas, and does not
distinguish between nonclassifiable
nonattainment and other nonattainment
areas. Consequently, EPA interprets the
transportation conformity rule's
reference to the need for nonattainment
areas to obtain a section 182(f)
exemption in order to be relieved of the
NOx conformity requirements to
include nonclassifiable ozone
nonattainment areas (i.e., submarginal,
transitional, incomplete/no data areas).
even though such areas are not subject
to Clean Air Act section 182(f) itself.
This means that ozone nonattainment
areas, including nonclassifiable ozone
nonattainment areas, can only be
exempted from the NOx provisions of
the transportation conformity rule if
EPA determines that the area satisfies
the substantive test required for an
areawide section 182(f) exemption,
through a process similar to that
required for section 182(f) exemptions
which are not related to conformity.
Thus, for nonclassifiable ozone
nonattainment areas outside the
Northeast ozone transport region, EPA
will consider requests for
determinations that additional NOx
reductions would not contribute to
attainment if such areas already have air
quality data that demonstrate attainment
of the ozone standard, that are
consistent with 40 CFRpart 58
requirements, and that are recorded in
EPA's Aerometric Information Retrieval
System (AIRS). Once made, this
determination would relieve an area of
the transportation conformity rule's
NOx provisions. A more thorough
explanation of the conditions and
monitoring-based section 182(0 and conformity
exemptions or. continued monitoring data that do
not show violations of the NAAQS. This will
provide an additional incentive for States to track
NOx emissions (and limit such emissions, where
necessary) to ensure that future violations do not
occur.
EPA notes that its conclusion regarding the
relevance of mriitenance may well be different for
other Clean Air Act provisions where the test is
whether emissions reduction measures are
"necessary" for attainment, even if maintenance is
not explicitly mentioned. See section 211(c)(4)(<3
(allowing States to overcome federal preemption of
State fuel controls where "necessary" to achieve a
NAAQS) and section I64(c) (providing for EPA
approval of ozone transport commission
recommendations of additional control measures
"necessary" to bring any area in the region into
attainment). It may make leas sense to disregard
maintenance la disallow more stringent fuel
controls under section 211 or to disapprove
additional controls under section 184 where these
measures not only contribute to but are "necessary"
for maintenance. The rationale that the State might
appropriately retain discretion to choose other
options to ensure maintenance makes less sense
when the specific measures in question are
"necessary."
process for obtaining the 182(f)
exemption is given in the May 27,1994
Seitz memorandum.
B. Condition on NOx Exemptions for
Areas Outside the Ozone Transport
Region With Monitoring Data
Demonstrating Attainment
If a NOx transportation conformity
exemption request is based solely on
monitoring data demonstrating
attainment, EPA's approval of the
exemption, if otherwise warranted, will
be granted on a contingent basis, i.e., the
exemption would last for only as long
as the area's monitoring data continues
to demonstrate attainment. If
subsequently it is determined that the
area has violated the standard, the
exemption, as of the date of the
determination, would no longer apply.
EPA would notify the state that the"
exemption no longer applies, and would
also provide notice to the public in the
Federal Register. Existing transportation
plans and TTPs and past conformity
determinations will not be affected by a
determination that the NOx exemption
no longer applies, but new conformity
determinations would have to observe
the NOx requirements of the conformity
rule. The State must continue to operate
an appropriate air quality monitoring
network, in accordance with 40 CFR
part 58, to verify the attainment status
of the area. The air quality data relied
on for the above determinations must be
consistent with 40 CFR part 58
requirements and other relevant EPA
guidance and recorded in EPA's
Aorometric Information Retrieval
System (AIRS).
C. Areas Inside an Ozone Transport
Region
Section 182(f) of the Clean Air Act
provides a different test for exempting
areas in an ozone transport region from
NOx requirements (see section I.C. of
this preamble). In particular, that test
requires a demonstration that shows
additional NOx reductions would not
produce net ozone benefits in the
transport region as a whole. Since the
requirement for meeting this test is
substantially different from that needed
to meet the contribute-to-attainment test
in section 182(f)(l)(A), and since the
language in the conformity rule clearly
does not reflect the language of the test
provided for areas in'an ozone transport
region, the determination of how such
areas would qualify for an exemption
from the rule's NOx requirements merits
more consideration before EPA can
issue appropriate guidance. Today's
guidance therefore applies only to NO\
exemptions for areas outside the Ozone
Transport Region.
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Federal Register / Vol. 59, No. 116 / Friday, June 17, 1994 / Notices
31241
As noted previously, requests for
conformity NOX exemptions must
consider the nonattainment area as a
whole. With respect to transportation
conformity, NOx exemptions will not be
granted for portions of nonattainment
areas. Therefore, nonattainment areas
with portions both inside and outside
the Ozone Transport Region will be
treated for purposes of such exemption
requests as areas inside the Ozone
Transport Region, and for the present
time, will not be eligible for an
exemption based on monitoring data as
described in this notice.
EPA will give further consideration to
areas in the Ozone Transport Region,
and if EPA does propose to exempt
some of these areas, they will be
addressed in state-specific nilemaking
notices unless another general preamble
providing guidance for such areas is
published first.
III. Process for Receiving a NOx
Exemption Based on Monitoring Data
for Nonclassifiable Areas
EPA believes that section 182(f) sets
up two separate procedures by which
EPA may act on NOx exemption
requests. Subsections 182(f) (1) and (2)
direct that action on NOX exemption
determination requests should take
place "when [EPA] approves a plan or
plan revision." This language appears to
contemplate that exemption requests
submitted under these paragraphs are
limited to states, since states are the
entities authorized under the Act to
submit plans or plan revisions. By
contrast, subsection 182(f)(3) provides
that "personls]1" may petition for a
NOx determination "at any time" after
the ozone precursor study required
under section 185B of the Act is
finalized,3 and gives EPA a limit of six
months after filing to grant or deny such
petitions. Although subsection 182(f)(3)
references section 182(f)(l), EPA
believes that paragraph (f)(3)'s reference
to paragraph (f)(l) encompasses only the
substantive tests in paragraph (f)(l)
(and, by extension, paragraph (f)(2)), not
the requirement in paragraph (f)U) for
EPA to grant exemptions only when
acting on plan revisions.
Accordingly, petitions submitted
under subsection 182(f)(3) are not
required to be submitted as state
implementation plan (SIP) revisions.
Consequently, the state is not required
under the Act to hold a public hearing
in order to petition for an areawide NOx
exemption determination under section
1 Section 302(e) of the Act defines the term
"person" to include states.
'The final section 185B report was issued )ul>-
30. 1993
182(f)(3) (see Clean Air Act sections
110(a) (1) and (2)). For similar reasons,
if the state is submitting an areawide
petition under subsection 182(f)(3), it is
unnecessary to have the Governor
submit the petition. However, because
of the need for consistency with the
AIRS data and the requirements of 40
CFR part 58, EPA believes that,
particularly in cases where the NO*
exemption request (including a request
for exemption from the NOx
requirements of the conformity rules) is
based on monitoring data, if such data
is contained in a petition submitted by
a person other than the state, the
petition should be coordinated with the
state air agency. Lack of endorsement by
the state air agency will require more
scrutiny by EPA, and therefore EPA's
processing of the petition will likely
take more time.
EPA will grant or deny a petition for
an areawide NOx transportation
conformity exemption through a full
nilemaking process. This may involve a
direct final rule or a notice of proposed
rulemaking followed by a final rule.
Either process allows opportunity for
public comment. For areas which are
relying on monitoring data which
demonstrates attainment, the notice and
comment will provide opportunity for
comment on the preliminary
interpretations contained in this General
Preamble. These rulemakings will also
offer opportunity for comment on the
appropriateness of using monitoring
data which is consistent with the
requirements in 40 CFR part 58 and
consistent with the data recorded in
AIRS as the basis of EPA's approval and
rescission of the contingent NOx
exemption. If EPA issues a final
rulemaking concluding that it will use
such air quality monitoring data in
making subsequent determination that
an area has violated the standard, no
further notice and comment will be
required in order to rescind the NOx
exemption in the event that such data
subsequently indicates that a violation
has occurred.
EPA is preparing a delegation of
authority to Regional Administrators to
make determinations under section
182(f) for arenas which are outside the
Ozone Transport Region and which
have three years of monitoring data
demonstrating attainment. This
delegation would allow the rulemaking
for 182(f) determinations to be
conducted by EPA's regional offices.
IV. Effect of a NOx Transportation
Conformity Exemption on
Transportation Planning
This section applies to both classified
and nonclassifiable areas.
Once EPA makes a finding under a
separate notice which grants a NO\
transportation conformity exemption, an
area is relieved of the transportation
conformity rule's requirements for
regional analysis of NOX emissions
However, EPA plans to amend the
transportation conformity rule to require
that once an area's maintenance plan is
approved, any previously approved
NOx conformity exemption no longer
applies. The area must then demonstrate
as part of its conformity determinations
that the transportation plan and TIP are
consistent with the motor vehicle
emissions budget for NOx where such &
budget is established by the
maintenance plan. As currently written,
none of the transportation conformity
rule's NOx requirements would ever
apply to an area once such an area had
received a NOx transportation
conformity exemption.
EPA believes that it is crucial for
maintenance areas to demonstrate
consistency with the maintenance
plan's motor vehicle NOx emissions
budget because that budget represents
the level of motor vehicle NOx
emissions needed for continued
maintenance. However, the
maintenance plan's NOx motor vehicle
emissions budget for the purposes of
transportation conformity will not
necessarily require annual NOx
emission reductions throughout the ten-
year period.
EPA intends to promptly amend the
conformity rule as stated above, so that
NOx motor vehicle emissions budgets m
maintenance plans will begin to apply
at the time or shortly after those plans
are approved.
V. Administrative Requirements
Regulatory Flexibility Act
Whenever EPA is required by section
553 of the Administrative Procedures
Act or any other law to publish general
notice and proposed rulemaking for er.\
proposed rule, EPA shall propose and
make available for public comment an
initial regulatory flexibility analysis
The regulatory flexibility
requirements do not apply for this
General Preamble because it is not a
regulatory action in the context of the
Administrative Procedures Act or the
Regulatory Flexibility Act.
Dated: June 8.1994.
Carol M. Browner,
/ dministrator.
|FR Doc. 94-14416 Filed 6-16-94, 6 45 tr.
BILLING CODE 6560-SO-P
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115
D-12
RACT and Innovative Control Technology Projects
(7-5-94 J. Seitz)
The Environmental Protection Agency has been asked to
consider whether a State may define RACT for nitrogen oxides
(NOx) as a phased program extending beyond May 31, 1995 for
sources that are actively developing innovative control
technology. Because of the important environmental benefits
associated with encouraging innovative technology, EPA has
determined that States may, in certain cases involving innovative
technology, define NOx RACT as a stage-by-stage program of
measures in order to accommodate the source's development and
installation of the innovative controls. This memorandum
provides guidance on .how EPA would process and approve innovative
such controls.
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7-5-94
MEMORANDUM
SUBJECT
FROM:
TO:
Reasonably Available Control Technology (RACT) and
Innovative Control Technology Projects
John S. Sietz, Director
Office of Air Quality Planning and Standards (MD-10)
Director, Air, Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
The Environmental Protection Agency (EPA) has been asked to
consider whether a State may define RACT for nitrogen oxides
(NOx) as a phased program extending beyond May 31, 1995 for
sources that are actively developing innovative control
technology. Because of the important environmental benefits
associated with encouraging innovative technology, EPA has
determined that States may, in certain cases involving innovative
technology, define NOx RACT as a stage-by-stage program of
measures in order to accommodate the source's development and
installation of the innovative controls.
Section 182(b)(2)(C) of the Clean Air Act (Act), as amended
in 1990, requires implementation of RACT as expeditiously as
practicable but no later than May 31, 1995. Sources that are
pursuing innovative control approaches that may not be available
for installation and commercial operation by this date have
sought to define NOx RACT as a phased program extending beyond
May 31, 1995. The EPA's general guidance concerning the phase-in
of controls beyond May 31, 1995 is stated in the NOx Supplement
to the General Preamble, 57 FR 55623, November 25, 1992. The
guidance provided in this memorandum is limited to those
situations where the source is currently pursuing an innovative
control technology strategy which promises to gain reductions
beyond existing NOx RACT measures and for which the application
of all or some of the controls by May 31, 1995 is impracticable.
In such cases, States can incorporate a phased NOx RACT program
into their State implementation plans (SIP's) by adopting a SIP
rule that allows for alternative compliance plans and which meets
the requirements contained in the NOx Supplement to the General
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Preamble and this memorandum. The EPA expects that the
additional time provided in this memorandum will not generally
exceed 12 to 18 months beyond May 31, 1995 and, in no event,
would exceed May 31, 1999.
For purposes of this guidance, innovative control technology
means any system of air pollution control that has not been
adequately demonstrated but which would have a substantial
likelihood of achieving greater continuous emissions reductions
than existing RACT. For instance, owners of internal combustion
engines have sought additional time to finalize NOx control
technologies that are currently under development and which
should achieve greater and less costly reductions than the
technology presently considered to be RACT. However, this new
technology would not be economically feasible if these sources
are also required to immediately install existing NOx RACT
measures.
In 1980, during implementation of the Act Amendments of
1977, EPA faced a similar issue for printers and similar sources.
At the time, several companies were developing low-solvent inks
and coatings as a means of meeting a RACT standard. While this
pollution prevention approach promised to provide greater
environmental benefits than add-on controls, it was not
reasonably available by the applicable deadline. The EPA
resolved the issue by allowing States to enter into alternative
compliance schedules with these sources, subject to a number of
safeguards and limitations (see memorandum, from Richard G.
Rhoads, Director, Control Programs Development Division, to
Director, Air and Hazardous Materials Division, Regions I - X,
dated April 25, 1980).
Similar to the printers' case noted above, EPA believes it
is appropriate to allow sources developing innovative control
technologies that promise greater emission reductions to phase-in
those controls over a period extending beyond May 31, 1995.
Under a phased-in approach, NOx RACT would be defined as a stage-
by-stage schedule of compliance steps including implementation of
all measures which can practicably be implemented by May 31,
1995, and subsequent implementation of other measures leading to
full implementation of the innovative technologies. The EPA
would regard all measures which are practicable for the affected
source (or set of sources) to implement by May 31, 1995 as RACT
as of that date. As other control measures become practicable to
implement at later times, EPA would regard such measures as RACT
as of those later dates. Thus, the SIP would require that
available noninnovative control measures be implemented on
schedules reflecting implementation as expeditiously as
practicable, but no later than May 31, 1995, and would require
that innovative technology be developed and installed on
schedules reflecting the earliest practicable development dates.
The following lists the criteria States must use in administering
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a phased RACT program.
1. Phased compliance is only available to a source (or set
of sources subject to single ownership) that is actively pursuing
innovative control technologies that would not be available by
May 31, 1995. The innovative technology must promise lower
emissions levels than the existing State SIP developed NOx RACT
measures and can consist of either innovative add-on controls,
process changes, or pollution prevention strategies. The State
must determine that the innovative technology under development
by a source is technically sound and sufficiently developed to
warrant a phased RACT approach. The EPA encourages States to
consult with the EPA Regional Offices in making this
determination.
2. The source and the State must agree to a specific phased
RACT compliance plan which includes:
An enforceable schedule of actions for making any
initial reductions that are compatible with the overall
innovative technology by a specified date reflecting installation
as expeditiously as practicable, but no later than May 31, 1995;
and
An enforceable schedule of actions culminating in
final installation and operation of the innovative control
technology by a specified date. The schedule for the innovative
technology must include clearly specified milestones reflecting
development and installation of the technology as expeditiously
as practicable. There must be a sufficient number of milestones
to ensure that work on the development of innovative technology
is being performed diligently and to enable the State and EPA to
monitor the progress of the development effort.
3. The compliance plan must contain an enforceable schedule
which requires the installation of existing NOx RACT measures by
a specified date if the source fails to diligently meet the
milestones contained in the phased RACT compliance plan or if the
innovative technology program fails to achieve the required
reduction levels.
4. The State must adopt and submit the compliance plan to
the EPA as a source-specific SIP revision. A SIP revision is
needed to make the requirements federally enforceable. As an
alternative to a source-specific SIP revision, States may make
the above phased RACT requirements for innovative technologies
enforceable by including them directly in the NOx RACT rule,
applicable on a case-by-case basis.
All inquiries regarding this policy should be addressed to
Tom Helms at (919) 541-5527.
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119
D-13
Clarification of Policy for NOx Substitution
(8-5-94 J. Seitz)
The purpose of this memorandum is to clarify past guidance
issued by the Environmental Protection Agency (EPA) on NOx
substitution for the post-1996 rate-of-progress (ROP) plans.
Specifically, this memorandum clarifies what the EPA will accept
as evidence that NOx substitution for volatile organic compounds
(VOC) redu2tions is a viable approach for meeting post-1996 ROP
requirements prior to completion of modeling supporting an area's
attainment demonstration.
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August 5, 1994
MEMORANDUM
SUBJECT: Clarification of Policy for Nitrogen Oxides (NOx)
Substitution
FROM: John S. Seitz, Director
Office of Air Quality Planning and Standards (MD-10)
TO: Director, Air Pesticides and Toxics Management
Division, Regions I and IV
Director, Air and Waste Management Division, Region II
Director, Air, Radiation and Toxics Division
Region III
Director, Air and Radiation Division, Region V
Director, Air, Pesticides and Toxics Division
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
The purpose of this memorandum is to clarify past guidance
issued by the Environmental Protection Agency (EPA) on NOx
substitution1'2 for the post-1996 rate-of-progress (ROP) plans.
Specifically, this memorandum clarifies what the EPA will accept
as evidence that NOx substitution for volatile organic compounds
(VOC) reductions is a viable approach for meeting post-1996 ROP
requirements prior to completion of modeling supporting an area's
attainment demonstration.
Background
When the NOx substitution guidance was developed, it was
assumed that required modeling attainment demonstrations would
generally be completed in a timely manner. Consequently, the
policy assumes that information produced by the demonstrations
'"Transmittal of NOx Substitution Guidance," memorandum from
John S. Seitz, Director, Office of Air Quality Planning and
Standards, to Air Division Directors, December 15, 1993.
2"Guidance on the Post-1996 Rate-of-Progress Plan and the
Attainment Demonstration," U.S. Environmental Protection Agency,
Office of Air Quality Planning and Standards, EPA-452/R-93-015,
January 1994.
-------
would be, in most cases, available to assist decision makers to
reach sound decisions concerning NOx substitution to meet post-
1996 ROP requirements.
Recent information from Regional Office modeling contacts
indicates that it is likely that some areas may not complete
their attainment modeling analyses by November 1994. Perhaps
even more significant, very few modeling demonstrations are
expected to be completed appreciably before the Act's
November 15, 1994 deadline for submitting State implementation
plan revisions reflecting ROP requirements and additional
measures needed to attain the national ambient air quality
standards (NAAQS). This latter possibility raises the likelihood
that there may be insufficient time prior to November 1994 to
take full advantage of information generated in the attainment
demonstration modeling to support a ROP plan reflecting partial
or full substitution of NOx for VOC reductions.
NOx Substitution Policy
The December 1993 NOx substitution guidance identifies
several prerequisites for NOx to be substituted, in part or in
full, for VOC reductions to satisfy ROP requirements. For
purposes of this discussion, the most pertinent of these appears
on pages 2 and 3, "States are required to justify substitution by
illustrating 'consistency' between the cumulative emission
changes emerging from the reasonable further progress/
substitution and the emission reductions in the model attainment
demonstration (or comparable modeling analysis)." The guidance
goes on to say on page 3 that, "The EPA will approve substitution
proposals on a case-by-case basis. Generally speaking, any
reasonable substitution proposal will be approved."
In the absence of a complete modeled attainment
demonstration, the following prerequisites are consistent with
the intent of the guidance on NOx substitution.
1. The NOx reasonably available control technology (RACT)
regulations should be adopted and submitted to the EPA by the
State seeking to substitute NOx for VOC to meet ROP requirements;
EPA will have to approve the NOx RACT rules no later than the
date of approval of the ROP plan featuring NOx substitution.
2. At least one of the two following conditions should be
met: (a) modeling of at least one episode should have been
completed with photochemical grid modeling which shows that NOx
reductions are useful in reducing ozone concentrations; or (b) a
regional modeling analysis supporting use of NOx controls to
reduce ozone within the area under consideration for use of NOx
substitution should be available.
-------
The first prerequisite shows that, indeed, NOx controls are
a part of the area's strategy to attain the ozone standard. The
prerequisite in 2(a) is preferable to that in 2(b), and will take
precedence, because it is more likely to reflect assumptions and
inputs to be used in the attainment demonstration. In any event,
either photochemical grid modeling or regional modeling results
are needed to show that NOx control is useful in helping an area
to attain the ozone NAAQS. It is only necessary to show this for
one of the episodes selected for the attainment demonstration.
This follows because the attainment strategy ultimately selected
must show predicted ozone to be less than or equal to 120 parts
per billion for all selected episodes.
Questions on this clarification may be directed to John
Silvasi at (919) 541-5666, or Ned Meyer at (919) 541-5594.
cc: Doug Grano
Tom Helms
Steve Hitte
William Hunt
Ned Meyer
Rich Ossias
Kimber Scavo
Laurel Schultz
John Silvasi
Joe Tikvart
Lydia Wegman
-------
123
D-14
De Minimis Values for NOx RACT
(1-1-95 T. Helms)
This memorandum presents information that is useful to
persons reviewing RACT rules with respect to de minimis values
for NOX RACT.
The RACT requirements apply to major stationary sources in
certain ozone nonattainment areas and throughout an ozone
transport region. A source generally consists of several units
which emit pollutants to the atmosphere. The sum of emissions
from all units at a facility determines if a unit is major and,
thus, subject to the RACT requirements. However, certain units
at a facility may be so small that it is clear that no controls
are reasonably available for those units, although RACT would
still apply at the other units within the facility.
-------
Signed Copy Dated January 1, 1995
MEMORANDUM
SUBJECT: De Minimis Values for NOx RACT
FROM: G. T. Helms, Group Leader
Ozone Policy and Strategies Group (MD-15)
To: Air Branch Chief, Region I - X
This memorandum presents information that we think would be
useful to you as you are reviewing RACT rules with respect to de
minimis values for NOX RACT. It was extensively coordinated with
the OGC and the NOx work group.
The RACT requirements apply to major stationary sources in
certain ozone nonattainment areas and throughout an ozone
transport region. A source generally consists of several units
which emit pollutants to the atmosphere. The sum of emissions
from all units at a facility determines if a unit is major and,
thus, subject to the RACT requirements. However, certain units
at a facility may be so small that it is clear that no controls
are reasonably available for those units, although RACT would
still apply at the other units within the facility.
Regulatory agencies have typically included exemptions for
very small emission units in their VOC RACT rules. The reason
for the exemptions is that control requirements at very small
units are generally not reasonable, considering technological and
economic feasibility. A 15 pound/day cut-off level first
appeared in 1966 in Rule 66 which was adopted by Los Angeles
County. The 3 pound/hour and 15 pound/day cut offs were
subsequently adopted into the Code of Federal Regulations, 40 CFR
part 51, Appendix B in 1971. After the first CTG's were issued,
EPA developed model regulations for VOC RACT. This guidance
appeared in April 1978 and included the 3 pound/hour and 15
pound/day exemptions for 15 VOC source categories. Unless
specified differently in other guidance, the EPA continues to
recommend these cut-off levels as criteria for regulatory
agencies to consider as they adopt or revise their VOC RACT
rules.
As a result of the new NOx RACT requirements in the Clean
Air Act Amendments of 1990, regulatory agencies are required to
develop and adopt NOx RACT rules. In the process of drafting
these rules, many agencies have included exemptions for very
small NOx emission sources for the same reason noted above for
VOC rules. Unlike the VOC rules, however, there is no well-
established precedent with respect to NOx. Further, the values
adopted by the various agencies include a wide range of exempt
sources. Thus, it is difficult to give a specific de minimis
value or range of such values for NOx as for VOC. The purpose of
-------
this memorandum is to provide technical data that may be used to
evaluate NOx de minimis for various categories of sources.
Technical data on NOx de minimis levels is contained in
attachments to this memorandum. The technical data are primarily
derived from information contained in the recently completed NOx
alternative control techniques (ACT) documents for four source
categories as follows:
Stationary Gas Turbines
Internal Combustion Engines
Process Heaters
Boilers (Watertube Boilers; Firetube Boilers)
These ACT documents provide comprehensive data on the full range
of potential NOx controls for each source category, including the
economic and technological feasibility of various control
processes.
In the evaluation of NOx de minimis levels, the following
factors should be considered:
1. Emission rates for various source sizes (for example
pound/hour).
2. Cost-effectiveness of controls.
3. Total emissions for a source category above various
cut-off levels
4. Total number of sources in a category above various
cut-off levels.
5. Exemptions contained in adopted State and local
regulations.
6. Units which meet the Act definition of a major source
should generally not be considered de minimis.
As a result of this review, EPA does not recommend specific
de minimis values, but presents the attached factors as a guide
in the development and review of State de minimis rules. In
addition, we strongly recommend that de minimis values be based
on more than one factor.
If you have any questions please contact Ted Creekmore of
Staff at 919-541-5699.
Attachment
cc: NOx Work Group Members, Sally Shaver
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ATTACHMENT 1
TECHNICAL DATA THAT MAY BE USED TO DETERMINE A DE MINIMIS RACT RULE FOR
PROCESS HEATERS
This information is from the "Alternative Control Techniques
Documents—NOx Emissions from for Process Heaters, " EPA-453/R-93-015,
February 1993.
Tables 1 lists the five criteria used to estimate de minimis
values. Table 1 also includes emissions of de minimis sources as a
percentage of overall emissions. Table 2 include emissions by size
(MMBtu/hr) of source. Table 3 gives cost effectiveness for the various
control measures and fuels burned by process heaters. Table 4 includes
a listing of State de minimis rules.
TABLE 1
NOx De Minimis Rules — Process Heaters
Emissions
by Size
ND:NG
50
MMBtu/hr=
4.9 Ib/hr
MD — 50
MMBtu/hr=
9.85
Ib/hr1
SEE TABLE
2
Cost Effect-
ness Envelop
See table 3
Number of
Sources
50 MM
Btu/hr (exem
pts about
50% of
sources)
Emission
s of
Sources
About
20% of
total
Process
Heater
Emission
s
State
Regulations
(MMBtu/hr)
MI <100
NJ
NY
DE <15
CA <5
See Table 4
Abbreviations
NG-Nitrogen Gas fired
ND-Natural Draft
MD-Mechanical Draft
'Emission factors for ND and MD process heaters are
different. However they are the same for all capacity sizes of
Process Heaters within each category.
-------
TABLE 2—Emissions by Size of Process Heater
Model
Capacity
(MMBtu/hr)
5
50
69
135
100
Natural2
Draft-
Natural Gas
Ib/hr
.49
4.9
6.7
13.2
9.8
Mechanical3
Draft-
Natural Gas
Ib/hr
.99
9.85
13.6
26.6
19.7
Natural4
Draft-Oil
Dist/Resid
Ib/hr
1.0
2.1
10.0
21.0
13.8
29.0
27.0
56.7
20.0
42.0
Mechanical5
Draft-Oil
Dist/Resid
Ib/hr
1.6
2.7
16.0
26.0
22.1
37.2
43.2
72.9
32.0
54.0
2EF:
3EF:
4EF:
5EF:
.098 Ib NOx MMBtu
.197 Ib/MMBtu
.20/.42 Ib/MMBtu
.32/.5S Ib/MMBtu
-------
TABLE 3—Cost Effectiveness Heat Inputs (MM BTU/hr)for $1300 per ton
for Process Heaters
Type
Control
LNB
ULNB
SNCR
SCR
LNB+FGR
Natural
Draft-
Natural Gas
75 (1430)
50(1300)
>186(2930)9
X
X
Mechanical
Draft-
Natural Gas
40(1330)
<40(1,020)8
263(1420)
>263(3710)
>263 (1720
Natural
Draft-Oil
Dist/Resid
>69(1680)6
<69(1190)
<69(892)
<69(420)
>69(2350)
<69(1230)
X
X
Mechanical
Draft-Oil
Dist/Resid
<135(658)7
<135(477)
<135(408)
<135(245)
135(1340)
<135(880)
>135(4160)
>135(2480)
<135(1170)
<135(961)
6This entry means: For LNB only one heat capacity was given,
69 MMBTU/hr. For distillate oil the size of a process heater
that would be cost-effective would probably be >69 MMBtu/hr since
the data shows a cost of $1680 at 69. For residual oil, the size
of a process heater that would be cost-effective would probably
be <69 because the cost at 69(1190) is below 1300.
7This entry means: For LNB only one heat capacity was given,
135 MMBTU/hr. For distillate oil the size of a process heater
that would be cost-effective would probably be <135 MMBtu/hr
because the cost at 135($658) is less than $1300. For residual
oil, the size of a process heater that would be cost-effective
would also probably be <135 because the cost at 135($477) is
below $1300.
8This entry means: For ULNB the lowest heat capacity given
was 40 MM Btu/hr where the cost is $1040 per ton of NOx removal.
Thus, ULNB is cost effective over the range of heat capacity
given (40-263 MM Btu\hr). In fact, since $1300 is the target
cost, a smaller process heater of <40 MM Btu/hr may be cost
effective.
9This entry means: For SNCR the highest heat capacity given
was 186 MM Btu/hr where the cost is $2980 per ton of NOx removed.
Thus, SNCR is not cost effective over the range of heat capacity
given (17-186).
-------
LNB+SNCR
LNB+SCR
>186(3150)
X
>263(1860)
>263(5530)
>69(2740)
<69(1430)
X
135(1490)
<135(942)
>135(3620)
>135(3190)
LNB—Low NOx Burner
UNLD—Ultra Low NOx Burners
SNCR—Selective Non-Catalytic Reduction
SCR—Selective Catalytic Reduction
LNB + FGR—LNB + Flue Gas Recirculation
X~No Data
TABLE 4—STATE PROCESS HEATER RULES—DE MINIMIS RULES
STATE /DATE
MI
NJ 11/17/93
3/25/94
NY 11/17/93
3/28/94
CA 3/28/94
Some
Districts
DE
RULE
< 100 MMBTU/hr
Overall: 25 t/y
< 137 Ibs/d 5/15-9/15
Overall: 3 Ibs/hr;
15 Ibs/day
5 MMBtu/hr or 1 MM Btu/hr
<15 MMBtu/hr
Sources Operating only
during the months November
through March.
COMMENT
Some Districts
Annual capacity
factor of less than
5%
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ATTACHMENT 2
TECHNICAL DATA THAT MAY BE USED TO DETERMINE A DE MINIMIS RACT RULE FOR
STATIONARY GAS TURBINES
This information is from the "Alternative Control Techniques
Documents—NOx Emissions from Stationary Gas Turbines," EPA-453/R-93-
007, January 1993, unless otherwise noted.
Tables 1 list five criteria used to estimate de minimis values.
Table 2 include emissions by power output of gas turbines. Table 3 give
cost effectiveness information for the natural gas and distillate oil
fuels burned by gas turbines. Table 4 gives estimates of the size and
relative power usage
of the four major source types. Table 5 includes a listing of State de
minimis values.
TABLE 1
NOx De Minimis Rules — Stationary Gas Turbines
Emissio
ns by
Size
Table
2
Cost
Effect-
ness
Envelop
Table 3
Number
of
Sources
Table 4
Emissions of Sources
Percent of total power for
gas turbines:
Standby /emergency: 2
Oil and gas industry: 7
Independ. elect, pow. : 4
Utilities: 87
For De Minimis value of
4.4 MW (15MMBtu/hr) , would
exclude:
Most standby /emergency,
Many oil and gas,
Some independ. elect, pow.
Few utilities turbines10
State
Regul
ation
s
Table
5
104.4 MW de minimis for example purposes, not necessarily
recommended.
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TABLE 2
Stationary Gas Turbines
Uncontrolled/Controlled Emissions by Size of Gas Turbines
Control Method: Water Injection
Gas Turbine
Model
Saturn
Centaur
Taurus
Mars T-12000
LM2500
GT10
MS7001E
MS7001F
Power11
Output
Megawatts
(MMBtu\hr
1.1(3.4)
3.3(11.3)
4.5(15.4)
8.8(30.1)
22.7(77.7
22.6(77.4
84.7(290)
161(551)
Dist.
Oil--
Uncontro
lied
Ib/hr
9.9
31.2
37.6
107
301
196
822
2190
Dist.
Oil--
Control
led
Ib/hr
4.1
10.8
13.9
24.9
37.9
42.6
243
417
Nat.
Gas —
Uncont
rolled
Ib/hr
6.4
22.0
24.7
69.4
146
143
544
1290
Natural
Gas —
Control
led
Ib/hr
2.8
7.4
9.4
17.0
36.4
24.6
154
267
nlMMBtu/hr equals .292 MW
-------
TABLE 3—Stationary Gas Turbines
Gas Turbine Power Output Corresponding to $1300 per ton12
Type Control
Water Injection (WI)
Steam Injection
Selective Catalytic Reduction
(SCR)13
WI + SCR
Dry Low NOx + SCR (9 ppm)
Dry Low-NOx
Natural Gas Power
Output — Megawatts
(MMBtu/hr)
17 (58.2)
11 (37.7)
42 ppm14
25 ppm15
60 (205)
11 (37.7)
418(11.7)
Light
Distillate Fuel
MMBtu/hr
12-14
8-9
42 ppm16
25 ppm17
42-46
No Reductions
No Reductions
12Boiler capacity is given in Megawatts (MW) with the
equivalent MMBtu/hr that corresponds to an estimated cost of
$1300 dollars per ton of NOx removed. Operating time is 8000
hrs/yr.
13Five year catalyst life assumed with the emission level for
the combination of controls estimated at 9 ppmv.
14Least expensive controls $3,580 at 161 MW (549.5 MMBtu/hr)
for control from 42 to 9ppmv.
15Least expensive controls at $6,980 at 83 MW (283.3
MMBtu/hr) for control from 25 to 9 ppmv.
16Least expensive controls $2649 per ton at 161 MW (549.5
Btu/hr) for control from 42 to 9 ppmv. Oil-fired cost
effectiveness is approximately .74 of gas fired. Thus, $3,580 X
.74 eguals $2649.
"Least expensive controls $5165 per ton at 83 MW (283.3
Btu/hr) for control from 25 to 9 ppmv. Calculated as in footnote
#7.
18Entire range below $1300; 4 MW is the lowest capacity
plotted.
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TABLE 4—NUMBER OF SOURCES FOR STATIONARY GAS TURBINES
19
Type of Source
Total Sources
Size Breakdown
Standby/Emergency
Electric Power
Generation
Estimated at 2% of
total power use for
1985 (2000 MW)
Large number of
turbine sales under
3.7 MW; operate on an
as need basis;
typically 75-200
hours\ yr. 1000 HP
(.74 MW) is
considered average
horsepower.
Oil and Gas Industry
Estimated at 7% of
total power use for
1985 (6000 MW)
Most turbines with
.08 - 15 MW range
(.27-51.4 MMBtu/hr)
(107-20,100 HP) most
operate continuously
8000 hrs/yr
Independent
Electrical Power
Producers
Estimated at 4% of
total power use for
1985 (3600MW)
Range of turbines 1-
100 MW; typically
operate between 4000
and 8000 hours/yr
Electric Utilities-
Peaking Units
Estimated at 87% of
total power use for
1985 (89,000 MW)
Range of turbines 15-
150 MW, most operate
less than 2000 hours/
yr
''information from EPA-450/2-77-017a, Standards Support and
Environmental Impact Statement Volume 1: Proposed Standards of
Performance for Stationary Gas Turbines, September 1977.
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TABLE 5—STATE BOILER DE MINIMIS RULES
STATIONARY GAS TURBINES20
STATE /DATE
LA 11/17/93
TX 11/17/93
NESCAUM
11/17/93
NJ 11/17/93
3/25/94
NY 11/17/93
3/28/94
CA 3/28/94
S. Coast
Bay Area
Kern County
DE
CN 3/28/94
NH 3/28/94
MASS 3/28/94
RULE
< 3 MW (10.3 MMBtu/hr)
< 10 MW (34.2 MMBtu/hr)
<25MMBtu/hr (7.3 MW)
<30 MMBtu/hr
Overall: 25 t/y
< 137 Ibs/d 5/15-9/15
<10 MMBtu/hr (2.92 MW)
<.3 MW (1.0 MMBtu\hr)
it
<10 MW (29.2 MMBtu\hr)
<450 hp (1.2 MMBtu/hr)
(.33 MW)22
<100 MMBtu/hr (29.2 MW)
< 25 MMBtu/hr
< 25 MMBtu/hr
COMMENT
maximum heat input rate
Waived if following cond.
present:21
facility-wide heat input
20Generally, it is not clear whether these de minimis values
refer to whole plants (NJ, NY) or individual units.
211. Insufficient water supply or water of unsuitable
quality; 2. No commercially available dry low-NOx combusters; 3.
RACT is annual tune-up.
22
1 HP equals .00074MW equals .00253 MMBtu/hr
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10
ATTACHMENT 3
TECHNICAL DATA THAT MAY BE USED TO DETERMINE A DE MINIMIS RACT RULE FO
INTERNAL COMBUSTION ENGINES
This information is from the "Alternative Control Techniques
Documents—NOx Emissions from Stationary Reciprocating Internal
Combustion Engines," EPA-453/R-93-032, July 1993, unless otherwise
noted.
Tables 1 list five criteria used to estimate de minimis values.
Table 2 include emissions by size of engines. Table 3 give cost
effectiveness information for the various types of 1C engines. Table 4
lists numbers of sources by the different fuels burned. Table 5
includes a listing of State de minimis rules.
TABLE 1
NOx De Minimis Rules — Internal Combustion Engines
Emissions
by Size
(hp)
See Table
2
Cost Effect-
ness Envelop
See Table 3
Number of
Sources
Table 4
Emissions of
Sources
Any De Minimis
in the range of
100-350 HP
Excludes about
95% of total
emissions for
spark ignition
engines
Diesels — 36% of
emissions below
De Minimis
value
State
Regulat
ions
(MMBtu/
hr)
DE <450
CA <50
Table 5
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11
TABLE 2—Emissions by Size of 1C engines
Size
Unit
HP
100
200
500
700
1000
1500
SI:
Rich-
Burn23
Ib/hr
3.48
6.96
17.4
34.75
SI: Lean
Burn24
Ib/hr
3.7
7.4
18.5
37
Gasoline25
Ib/hr
1.14
2.28
5.70
Diesel
Ib/hr26
2.65
5.30
13.23
18.55
26.5
Dual
Fuel
Ib/hr27
13
18.7
28
25
26
27
= 13.9 t/y based on 8000 annual operating hours
=14.8 t/y based on 8000 annual operating hours.
EF = 5.16 g/hp-hr from AP-42
EF = 10.6 t/y based on 8000 annual operating hours.
EF = 52.4 t/y based on 8000 annual operating hours.
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12
TABLE 3
Cost Effectiveness Horsepower for $1300 per ton for 1C Engines
Type
Control
AF
IR
AF+IR
NSCR or
PSC
L-E Med
L-E low
SCR
(low)
Spark Ignition
(SI) (NG)
Rich Lean
Burn Burn
200
200
20030
500-700
8031
1000
No Data
700
500
700
20032
900
1400
SI
Gaso-
line28
ND
ND
ND
ND
ND
ND
ND
Compression
Ignition
Dual-
Diesel Fuel
250
1900
70029
> 130033
3500
Abbreviations:
AF Air/Fuel Adjustments
IR Ignition Timing Retard
NSCR Nonelectric Catalytic Reduction
PSC Prestratified Charge
SCR Selective Catalytic Reduction
L-E Low Emission Combustion Design34
A/F+IR Parametric
NG Natural Gas
28Assume cost effectiveness similar to Natural Gas SI
engines.
29Entire range below $1300; 700 HP lowest plotted.
30More flexibility in adjusting engine than just IR or AF.
31Entire range below $1300; 80 is lowest HP plotted.
32Entire range below $1300; 200 is the lowest HP plotted.
33Least expensive controls cost $2200 per ton at about 7000
HP.
^Generally apply to new sources, not off the shelf
technology for most existing sources.
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13
TABLE 4—NUMBER OF SOURCES FOR 1C ENGINES
Fuel Burned
Total Sources
Size Breakdown
Natural Gas
294,000
266,000 (90%) average
HP is = 15
<_ 200 HP 94% of
sources
Gasoline
64,100,000
63,000,000 (98%)
average HP is 4
<_200 HP Almost 100%
of sources
Largest 40,000
sources averaged 150
HP
Diesel Oil
35
606,000
545,000 <_ 350 HP or
90%
381,000 <_ 250 HP or
63%
35
Duel Fuel Sources included with Diesel data.
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14
TABLE 5—STATE 1C RULES
STATE/ DATE
LA 11/17/93
TX 11/17/93
NESCAUM
11/17/93
NJ 11/17/93
3/25/94
NY 11/17/93
3/28/94
CN 3/28/94
CA 3/28/94
S. Coast
Ventura
San Diego
SF Bay Area
S. Basin
NH 3/28/94
MASS 3/28/94
RI 3/24/94
RULE
> 300 hp
_> 150 hp Houston
> 300 hp Beaumont
_> 3 MM BTU/hr (1178 hp)36
_> 500 hp;
Overall: 25 t/y
< 137 Ibs/d 5/15-9/15
_> 225 hp for Severe Area
_> 400 hp rest of State
Overall: 3 Ibs/hr;
15 Ibs/day
3 MM BTU (1178 hp)
> 50 bhp
> 50 bhp
> 200 bhp
> 250 bhp
> 50 bhp
4.5 MMBTU (1768 hp)
3 MMBTU (1178 hp)
operate >1000 hrs per yr
> 400 hp
COMMENT
^Conversion Factor: 392.7 HP/MM Btu/hr
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15
ATTACHMENT 4
OVERVIEW OF BOILER CATEGORIES37
Class/Type
Fuel
Commercial
Institut .
Industrial
Watertube
Firetube
Cast Iron
.Coal
Residual
Distillate
Nat. Gas
Capacity
Range
(MMBtu/hr)
.4-10
10 - 1500
.4 - 1500
.4 - 50
.4 - 10
Number of
Boilers
1,295,130
506,930
50,495
275,075
1,476,490
214,00
389,104
244,206
954,350
Total
Capacity
(MMBtu/hr)
1,374,690
3,107,440
2,552,500
1,033,300
896,200
815,830
1,223,800
433,600
2,008,500
Percent of
Total
Capacity
31
69
57
23
20
18
27
10
47
37Data from EPA-600/7-79-178a, Population Characteristics of
Industrial/Commercial Boilers in the U.S., August 1979.
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16
ATTACHMENT 5
TECHNICAL DATA THAT MAY BE USED TO DETERMINE A DE MINIMIS RACT RULE FOR
WATERTUBE BOILERS (REVISED 10/17/94)
This information is from the "Alternative Control Techniques
Documents—NOx Emissions from Industrial/Commercial/Institutional (ICI)
Boilers," EPA-453/R-94-022, March 1994, unless otherwise noted.
Tables 1 list five criteria used to estimate de minimis values.
Table 2 include emissions by size of boilers. Table 3 give cost
effectiveness information for the various fuels burned by watertube
boilers. Table 4 lists numbers of sources by the different fuels
burned. Table 5 includes a listing of State de minimis values.
TABLE I
NOx De Minimis Rules — Watertube Boilers
Emissio
ns by
Size
(MMBtu/
hr)
Table
2
Cost
Effect-
ness
Envelop
Table 3
Number
of
Sources
Table 4
Emissions of Sources
Watertube boil, are about
6% of total ICI boilers
About 30% of ICI boiler
capacity
For de minimis value of 10
MMBtu/hr, this would
exclude:
NG: 33%
DIST 56%
RESID 28%
COAL 0%
State
Regul
ation
s
(MMBt
u/hr)
Table
5
ADoreviations:
NG Natural Gas;
RESID Residual Oil;
DIST
Distillate Oil;
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17
TABLE 2
Watertube Boilers
Uncontrolled Emissions by Size of Boilers(Ib/hr)
Size
Unit
MMBtu
/hr
1
5
10
100
O RH
Coal38
0.69
3.45
6.90
69.0
1 1 O
L 1 100
0.13
0.65
1.30
13. OO/
21.00
___ /
/
52.50
Natural
Gas41
< 100/
>100
0.14
0.70
1.40
14.00
_____ /
/
65.00
38EF = 0.69 Ib/MMBtu based on .70 Capacity factor or 5600
operating hours per year.
39EF = .36 Ib/MMBtu
40EF = .13 Ib/MMBtu, 10—100 MMBtu/hr; .21 Ib/MMBtu, >100,
41EF = .14 lb MMBtu <_ 100 MMBtu/hr; .26 Ib MMBtu >100.
-------
18
TABLE 3—Watertube Boilers (Single Burners-Packaged)
Boiler Size Corresponding to $1300 per ton42
Type
Control
SNCR
SCR
OT+WI
OT+SCA
LNB
LNB+FGR
Natural Gas
.66C .50C
ND
43
1049
ND
10
75
ND
44
1049
ND
175
240
Distill. Oil
.660 .500
ND
45
ND
ND
10
25
ND
46
ND
ND
160
250
Residual Oil Pul Coal
.66C .50C .66/.50C
ND
140
ND
ND
10
10
ND
47
ND
ND
50
200
250/250
48
ND
ND
250/600
ND
Abbreviations:
.66C .66 Capacity Factor .50
ND No Data Pul
SNCR Selective NonCatalytic Reduction
SCR Selective Catalytic Reduction
OT+WI Oxygen Trim + Water Injection
OT+SCA OT + Staged Combustion Air
LNB Low NOx Burners
LNB+FGR Low Nox Burners + Fluid Gas Recirculation
.50 Capacity Factor
Pulverized
"Boiler capacity is given in MM Btu/hr that corresponds to
an estimated cost of $1300 dollars per ton of NOx removed.
Capacity factor: .66/.50. Costs based on 10 percent interest and
10 year capital amortization in 1992 dollars. Does not include
the impact of Continuous Emission Monitoring systems, required on
larger source in some areas.
"Least expensive controls $1800 at 250 MM Btu/hr.
44Least expensive controls $3900 per ton at 250.
45Least expensive controls cost $2180 per ton at 250
MMBtu/hr.
46Least expensive controls cost $4100 per ton at 250
MMBtu/hr.
47Least expensive controls cost $2190 at 250 MMBtu/hr.
"Least expensive controls $3000/3700 at 750 MMBtu/hr.
"Entire range below $1300; 10 is lowest capacity plotted.
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19
TABLE 4—NUMBER OF SOURCES FOR WATERTUBE BOILERS
50
Fuel Burned
Coal: Pulverized
Natural Gas
Distillate
Residual Oil
Total Sources
733
18,291
8,000
15,953
Size Breakdown
>250 MMBtU/hr — 36%
>100 " — 100%
>250 MMBtu/hr — 3%
>100 " — 11%
<10 " — 33%
>250 MMBtu/hr — 1%
>100 " — 3%
<10 " — 56%
>250 MMBtu/hr — 2%
>100 " — 10%
<10 " — 28%
'"information from EPA-600/7-79-178a, Population and
Characteristics of Industrial/Commercial Boilers in the U.S.,
August 1979. Includes both packaged and field-erected watertube
boilers. Cost-effective data in Table 3 is only for single-
burner packaged boilers.
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20
TABLE 5--STATE BOILER DE MINIMIS RULES FOR INDUSTRIAL/COMMERCIAL BOILERS
(INCLUDES WATERTUBE AND FIRETUBE)51
STATE /DATE
OH
MI
LA 11/17/93
TX 11/17/93
NESCAUM
11/17/93
NJ 11/17/93
3/25/94
NY 11/17/93
3/28/94
CN 3/28/94
CA 3/28/94
S. Coast
Ventura
San Diego
SF Bay Area
S. Basin
NH 3/28/94
MASS 3/28/94
MA 3/28/94
RI 3/24/94
RULE
<10 MMBtu/hr
<_100 MMBtu/hr
<_80 MMBtu/hr
<_100 MMBtu/hr
50 — 100 MBtu/hr case by
case
Overall: 25 t/y
< 137 Ibs/d 5/15-9/15
Overall: 3 Ibs/hr;
15 Ibs/day
< 5 MMBTU/hr
< 2 MMBtu/hr
<_ 1 MMBtu/hr
<_ 5 MMBtu/hr
<_ 1 MMBtu/hr
<_ 5 MMBtu/hr
< 30 MMBTU
< 20 MMBtu/hr (with PTE
<25 TPY)
operate >1000 hrs per yr
< 50MMBtu/hr
< 50 MMBtu/hr-only tuneups
required
COMMENT
only tuneups
required
Varies from 2-5
MMBtu/hr
1-5 MMBtu/hr
1-5 MMBtu/hr
51Generally, it is not clear whether these de minimis values
refer to whole plants (NJ, NY) or individual units.
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21
ATTACHMENT 6
TECHNICAL DATA THAT MAY BE USED TO DETERMINE A DE MINIMIS RACT RULE FOR
FIRETUBE BOILERS
This information is from the "Alternative Control Techniques
Documents—NOx Emissions from Industrial/Commercial/Institutional (ICI)
Boilers," EPA-453/R-94-022, March 1994, unless otherwise noted.
Table 1 list five criteria used to estimate de minimis values.
Table 2 include emissions by size of boilers. Table 3 give cost
effectiveness information for the various fuels burned by watertube
boilers. Table 4 lists numbers of sources by the different fuels
burned. Table 5 includes a listing of State de minimis rules.
RECOMMENDATIONS
TABLE 1
NOx De Minimis Rules — Firetube Boilers
Emissio
ns by
Size
Table 2
Cost
Effect-
ness
Envelop
Table 3
Number
of
Sources
Table 4
Emissions of Sources
Firetubes boil, are about
15% of total ICI boil.;
About 54% of ICI boil.
capacity nationwide.
For Di minimis value of 25
MMBtu/hr, this would
exclude:
99% of sources from NG,
DIST, RESID. COAL?
State
Regula
tions
Table
5
Abbreviations
NG Natural Gas;
RESID Residual Oil;
DIST
Distillate Oil;
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22
TABLE 2
Firetube Boilers52
Uncontrolled Emissions by Size of Boilers(Ib/hr)
Size
Unit
MMBtu
/hr
1
5
10
100
250
Coal53
0.61
3.05
6.10
61.0
165.25
Residual
Oil54
0.31
1.55
3.10
31.00
77.50
Distillat
Oil55
0.17
0.85
1.70
17.00
42.50
Natural
Gas56
0.10
0.50
1.00
10.00
25.00
year.
52Based on .70 Capacity factor or 5600 operating hours per
i
53EF = 0.61 Ib/MMBtu for tangential fired boilers.
MEF = .31 Ib/MMBtu
55EF = .17 Ib/MMBtu/hr.
56EF = .10 Ib MMBtu.
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23
TABLE 3—Firetube Boilers (Single Burners-Packaged)
Boiler Size Corresponding to $1300 per ton57
Type
Control
OT+WI
OT+FGR
LNB65
^NB+FGR
Natural Gas
.66C .50C
58
60
10
75
59
61
175
240
Distill. Oil
.66C .50C
ND
62
10
25
ND
63
160
250
Residual Oil Pul Coal
.66C .50C .66/.50C
ND
30
10
10
ND
64
50
200
ND
ND
250/250
ND
Abbreviations:
.66C .66 Capacity Factor .50
ND No Data Pul.
OT+WI Oxygen Trim + Water Injection
OT+FGR OT + Fluid Gas Recirculation
LNB Low NOx Burners
Range of Reductions:
OT + WF—15%(OT) + WR (55%)
OT + FGR-15% " + FGR (40%)
.50 Capacity Factor
Pulverized
57Boiler capacity is given in MM Btu/hr that corresponds to
an estimated cost of $1300 dollars per ton of NOx removed.
Capacity factor: .66/.50. Costs based on 10 percent interest and
10 year capital amortization in 1992 dollars. Does not include
the impact of Continuous Emission Monitoring systems, required on
larger source in some areas.
58Least expensive controls $2400 per ton at 33.5 MM Btu/hr.
59Least expensive controls $2890 at 33.5 MMBtu/hr.
^Least expensive controls $3000 at 33.5 MMBtu/hr.
6ILeast expensive controls $4080 at 33.5 MMBtu/hr.
62Least expensive controls $1500 at 33.5 MMBtu/hr.
"Least expensive controls $2150 at 33.5 MMBtu\hr.
"Least expensive controls $1460 at 33.5 MMBtu\hr.
65No cost estimates made, cost effectiveness estimated to be
the same as for watertube units, page 6-22 of EPA-453/R-94-022.
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24
TABLE 4—NUMBER OF SOURCES FOR FIRETUBE BOILERS66
Fuel Burned
Total Sources
Size Breakdown
Coal
26,328
>50 MMBtu/hr—0
25-50 " —1%
<10 " —93%
<1.5 " —73%
Natural Gas
126,923
>50 MMBtu/hr—0%
25-50 " —1%
<10 " —92%
<1.5 " —66
Distillate
48,141
>50 MMBtu/hr—0%
25-50 " —1%
<10 " —92%
<1.5 " —63
Residual Oil
73,683
>50 MMBtu/hr—0%
25-50 " —1%
<10 " —92%
<1.5 " —63%
^Informations form EPA-600/7-79-178a, Population and
Characteristics of Industrial/Commercial Boilers in the U.S.,
August 1979.
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25
TABLE 5—STATE BOILER DE MINIMIS RULES FOR INDUSTRIAL/COMMERCIAL BOILERS
(INCLUDES FIRETUBE AND WATERTUBE)67
STATE /DATE
OH
MI
LA 11/17/93
TX 11/17/93
NESCAUM
11/17/93
NJ 11/17/93
3/25/94
NY 11/17/93
3/28/94
CN 3/28/94
CA 3/28/94
S. Coast
Ventura
San Diego
SF Bay Area
S. Basin
NH 3/28/94
MASS 3/28/94
MA 3/28/94
RI 3/24/94
RULE
<10 MMBtu/hr
<_100 MMBtu/hr
<_80 MMBtu/hr
<_100 MMBtu/hr
50 — 100 MBtu/hr case by
case
Overall: 25 t/y
< 137 Ibs/d 5/15-9/15
Overall: 3 Ibs/hr;
15 Ibs/day
< 5 MMBTU/hr
< 2 MMBtu/hr
< 1 MMBtu/hr
<_ 5 MMBtu/hr
< 1 MMBtu/hr
< 5 MMBtu/hr
< 30 MMBTU
< 20 MMBtu/hr (with PTE
<25 TPY)
operate >1000 hrs per yr
< 50MMBtu/hr
< 50 MMBtu/hr-only tuneups
required
COMMENT
only tuneups
required
Varies from 2-5
MMBtu/hr
1-5 MMBtu/hr
1-5 MMBtu/hr
67Generally, it is not clear whether these de minimis values
refer to whole plants (NJ, NY) or individual units.
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151
D-15
Scope of NOx Exemptions
(1-12-95 T. Helms)
This memorandum addresses the effects of EPA action to grant
an exemption under section 182(f) of the Clean Air Act.
Specifically, the issue was raised as to whether a NOx exemption
can be made applicable only to NOx Reasonably Available Control
Technology (RACT). As described below, where EPA grants a NOx
exemption under section 182(f), the exemption applies to RACT,
nonattainment New Source Review (NSR), conformity; and
inspection/maintenance (I/M).
(Note: This has been modified for conformity—see 60 FR 57179,
11-14-95.)
-------
Signed Copy Dated 1/12/95
MEMORANDUM
SUBJECT: Scope of Nitrogen Oxides (NOx) Exemptions
FROM: G.T. Helms, Group Leader
Ozone/Carbon Monoxide Programs Branch (MD-15)
TO: Air Branch Chiefs, Region I - X
This memorandum addresses the effects of EPA action to grant
an exemption under section 182(f) of the Clean Air Act. It was
coordinated with the Office of General Counsel (OGC) and NOx Work
Group. Specifically, the issue was raised as to whether a NOx
exemption can be made applicable only to NOx Reasonably Available
Control Technology (RACT). As described below, where EPA grants
a NOx exemption under section 182 (f), the exemption applies to
RACT, nonattainment New Source Review (NSR), conformity; and
inspection/maintenance (I/M).
Section 182(f) provides three cases where the NOx
requirements shall not apply: (1) net air quality benefits, (2)
contribution to attainment, and (3) net ozone benefit. If EPA
determines that any one of the three cases applies, the section
182(f) NOx requirements "shall not apply." The section 182(f)
NOx requirements are RACT (section 182(b))1 and nonattainment NSR
(section 173)2. Thus, where one of the three cases applies and
the exemption is granted by EPA, the affected sources are no
longer required to meet either the NOx RACT or nonattainment NSR
requirements.
In addition section 182 (f) provides a separate mechanism to
fine tune the NOx exemption. That is, under the "excess
reductions" provision in section 182(f)(2), EPA may "limit the
application of section 182(f) to the extent necessary to avoid
achieving such excess reductions." Thus, where EPA grants a NOx
exemption under the "excess reductions" provision, the exemption
could be for RACT only and not NSR. Further, under this
provision, an exemption could be granted for certain RACT
categories while RACT could be applied to other categories.
Where EPA grants an areawide exemption under section 182(f),
other effects apply beyond RACT and NSR. As stated in EPA's
inspection and maintenance (57 FR 52950) and conformity rules (58
FR 62188 for transportation rules and 58 FR 63214 for general
rules), certain NOx requirements do not apply where EPA granted
!EPA discusses economic and technical feasibility guidance
for determining NOx RACT in Section 4 of 57 FR 55624.
2EPA discusses Nonattainment NSR requirements which include
Lowest Achievable Emission Reductions and emission offsets under
57 FR 55623.
-------
an areawide exemption under section 182(f). This exemption
automatically applies; i.e., a State does not need to request the
application or granting of the inspection/maintenance or
conformity exemptions.3
As Regional Offices develop and complete rulemaking actions
on NOx exemption requests, the rulemaking notices should clearly
state all the effects of the EPA action consistent with the
requirements of the Administrative Procedure Act (APA). The APA
requires, for example, rulemaking notices to include either the
terms or substance of the proposed rule or a description of the
subjects and issues involved [section 553(b)]. For example, the
July 26, 1994 Federal Register for Ohio (59 FR 37948) describes
the rulemaking effects as follows:
This action exempts the Toledo and Dayton areas from the
requirements to implement NOx RACT requirements,
nonattainment area new source review for new sources and
modifications that are major for NOx, and the applicable
general and transportation conformity provisions for NOx.
For the Toledo nonattainment area, a Basic I/M program is
required. This approval allows the basic I/M NOx requirement
to be omitted from the program. For the Dayton
nonattainment area, the State has adopted an enhanced I\M
program. Based on this approval, NOx emission reductions
are not required of this program (however, the program shall
be designed to offset NOx increases resulting from the
repair of HC and CO failures).
The rulemaking actions should also note that EPA approval of
a NOx exemption is granted on a contingent basis. That is, the
exemption would last for only as long as the area continued to
demonstrate attainment without NOx reductions from major
stationary sources (or is redesignated to attainment). For
example language regarding a monitoring based exemption, see 59
FR 37948. For example language regarding a modeling based
exemption, see the November 28, 1994 Federal Register for Texas
(59 FR 60713) .
If you have any questions, please contact Ted Creekmore of
my staff at 919-541-5699.
cc: Richard Ossias
Sally Shaver Phil Lorang
John Bachmann NOx Work Group Members
3The section 182(f) exemption does not affect EPA's
requirements for maintenance plans; the maintenance plan required
for redesignation must still address NOx in accordance with EPA
guidance.
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154
D-16
Section 182(f) NOx Exemptions—Revised Process and Criteria
(2-8-95 J. Seitz)
This memorandum clarifies guidance previously issued
concerning NOx exemptions under section 182(f) of the Clean Air
Act (Act) and interstate transport of emissions under section
110(a)(2)(D) of the Act. It decouples NOx exemptions under
section 182(f) from interstate transport of emissions under
section 110(a)(2)(D), and reiterates policy in document 17 (D-17)
under the office directors signature. The policy in D-17 states
that, "where EPA grants a NOx exemption under section 182(f), the
exemption applies to RACT, nonattainment new source review,
conformity, and inspection/maintenance.
(Note: This guidance has been modified for conformity—see 60 FR
57179, 11-14-95.)
-------
February 8, 1995
MEMORANDUM
SUBJECT
FROM:
TO:
Section 182(f) Nitrogen Oxides (NOx) Exemptions—
Revised Process and Criteria
John S. Seitz, Director
Office of Air Quality Planning and Standards (MD-10)
Director, Air, Pesticides and Toxics Management
Division, Regions I and IV
Director, Air & Waste Management Division, Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air & Radiation Division, Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air & Toxics Division,
Regions VII, VIII, IX, and X
This memorandum clarifies guidance previously issued
concerning NOx exemptions under section 182(f) of the Clean Air
Act (Act) and interstate transport of emissions under section
110(a)(2)(D) of the Act.1 First, the EPA believes that these two
sections must be considered independently. Under section 182(f),
an exemption from the NOx requirements may be granted for
nonattainment areas outside an ozone transport region if EPA
determines that "additional reductions of [NOx] would not
contribute to attainment of the national ambient air quality
standard for ozone in the area." The EPA believes that the term
"area" means the "nonattainment area" and that EPA's
determination is limited, as a legal matter, to consideration of
the effects in the nonattainment area due to NOx emissions
reductions from sources in the same nonattainment area. The EPA
has separate authority under section 110(a)(2)(D) to require a
State to reduce emissions from stationary and/or mobile sources
where there is evidence showing that such emissions would
contribute significantly to nonattainment or interfere with
maintenance in other States. In some cases, then, EPA may grant
an exemption from across-the-board NOx reasonably available
control technology (RACT) controls under section 182(f) and, in a
separate action, require NOx controls from stationary and/or
mobile sources under section 110(a)(2)(D). The guidance
1 Guideline for Determining the Applicability of Nitrogen
Oxide Requirements under Section 182(f). Office of Air Quality
Planning and Standards, Air Quality Strategies & Standards
Division, December 1993, Chapter 4, "Contribute to Attainment."
-------
contained in this memorandum replaces the last paragraph of
section 4.4 and supplements section 4.3 of the December 16, 1993
guidance.
Secondly, where EPA grants a NOx exemption under section
182(f), the exemption applies to RACT, nonattainment new source
review, conformity, and inspection/maintenance. Further
discussion of this issue may be^ found in a January 12, 1995
memorandum from G. T. Helms to the Regional Air Branch Chiefs.
cc: Rich Ossias
-------
157
D-17
Letter from John Seitz, Director, Office of Air Quality
Planning and Standards to Bruce Carhart, Executive Director,
Ozone Transport Commission
(9-12-95)
The letter provided a formal response to Mr. Carhart's
September 16, 1994 letter, which posed specific questions on
interstate trading and new source review (NSR) under the nitrogen
oxides (NOx) emissions budget concept. Major issues discussed
are as follows:
-Geographical and Interstate Considerations
-New Source Review Considerations
Identical letters were sent to Mr. Jason Grumet, Northeast States
for Coordinated Air Use Management and to Mr. James Hambright,
Mid-Atlantic Regional Air Management Association
-------
USB
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK. NC 27711
SEP 12 1995
OFFICE OF
.,_._,, Aia QUALITY PLANNING
Mr. Bruce Carhart AND STANDARDS
Executive Director*
Ozone Transport Commission
444 N. Capitol Street, N.W., Suite 604
Washington, D.C. 20001
Dear Mr. Carhart:
The purpose of this letter is to provide a formal response
to your September 16, 1994 letter, which poses specific questions
on interstate trading and new source review (NSR) under the
nitrogen oxides (NOx) emissions budget concept. The
Environmental Protection Agency (EPA) is very supportive of the
efforts of the Ozone Transport Commission, the Northeast States
for Coordinated Air Use Management, and the Mid-Atlantic Regional
Air Management Association to develop a flexible and vigorous
market-based NOx emissions budget program that will reduce
regional ozone concentrations in a cost-effective manner. We
believe there are no major impediments to the development of a
budget program in the Ozone Transport Region (OTR) that satisfies
enforcement issues and meets the requirements of State
implementation plans (SIP). In developing this guidance on your
specific questions, we have been working closely with your
organizations over the last several months on these and other NOx
budget issues. Our response to each of these issues is outlined
below.
Geographical and Interstate Considerations
Your letter asks the EPA to identify any geographical
limitations related to trading within the OTR, specifically
related to interzone and interstate trading under a NOx budget.
In general, such trading may be unconstrained in the majority of
cases; nevertheless, it is important that trading programs
contain appropriate safeguards to assure that SIP requirements
continue to be met for reasonable further progress (RFP) and/or
attainment and maintenance plans during implementation of the
trading program. In addition, appropriate provisions must be
adopted for enforcement of interstate trading.
Trades could impact RFP requirements in serious and severe
ozone nonattainment areas which choose to meet RFP through NOx
substitution. However, the NOx RFP requirement might be met
through implementation of the September 27, 1994 NOx Memorandum
of Understanding (MOU) which calls for substantial NOx
reductions. That is, in many areas the RFP portion of NOx
reductions might be small compared to the overall NOx reductions
from stationary sources in the nonattainment area.
-------
The EPA views trades in areas with attainment or maintenance
plans which include a regional strategy (such as the NOx MOU), as
generally consistent with the regional concept in the SIP.
However, the EPA is concerned that the cumulative effect of
trades over the long term could create a situation that was not
possible to foresee at the start of the trading program but needs
correction. Therefore, the SIP trading program should include
commitments for tracking of changes in the NOx emissions and, as
needed, remodeling and revision of the SIP.
In evaluating the effect of trades on the attainment or
maintenance plans, the EPA will place greatest emphasis on the
overall effect of all trades, rather than examination of
individual trades. Our initial analysis of this issue (August
1995 draft report by ICF Resources) is encouraging in this
respect. It appears that broad geographic constraints on trading
within the OTR, such as interzone limitations, may not be needed.
In some cases, however, States might have information concerning
the effects of NOx reductions in specific local areas. In such
cases, states might choose to include in their trading program
specific provisions governing NOx trades in those areas.
To assure an equitable and enforceable program, an
interstate trading program needs a regional mechanism for the
tracking of trades in order to avoid any double counting of
emission reductions. Further, interstate trading should
generally be founded upon SIP trading rules that are
substantively identical so that an emission credit in one State
is creditable in another State.
New Source Review Considerations
Regarding the NSR offset requirement for major new and
modified stationary sources, the EPA's general policy is that
credits for emissions reductions generated by stationary, mobile,
or area sources may be used so long as they meet the offset
provisions of section 173 of the Act and the EPA's NSR
regulations. Where possible under section 173(c), the EPA
intends that States have the flexibility to design market based
programs that include provisions for NSR offsets. The specific
provisions of section 173(c) could be built into a market based
approach. For example, the "contribute to a violation of the
national ambient air quality standard" provision of section
173(c)(l)(B) might be addressed upfront in the plan by specifying
specific areas or zones in the plan area from which offsets could
be obtained.
The EPA has decided to take a more flexible interpretation
of section 173(c) as applied in the ozone attainment areas in the
OTR than the initial position in our letter to you dated March
31, 1993. Section 184(b)(2) requires that new or modified major
sources locating in ozone attainment areas in the OTR must meet
the same NSR requirements as if the source were locating in a
-------
Moderate ozone nonattainment area. For the OTR, the EPA believes
that States have the flexibility to allow emissions reductions
from ozone attainment areas in the OTR to be used as NSR offsets
in ozone nonattainment areas classified as Moderate (or below),
so long as the contributions test of section 173(c)(l)(B) is met.
Also, the equal or higher classification" provisions of section
173(c)(1)(A) still apply.
Furthermore, the EPA understands that under consideration in
the NOx Budget proposal is a "seasonal" budget program for the 5-
month ozone season. The EPA is willing to discuss further the
details of a program that allows emissions reductions below
seasonal budget allocations as NSR offsets provided there is
periodic reconciliation by the State(s) that the total increased
emissions from new or modified sources in the budget area is
sufficiently offset by actual emissions at the proper offset
ratio.
Our collaborative efforts are clearly helping to develop a
NOx trading program that will provide a significant step toward
attainment of the ozone standard in a cost-effective manner. I
look forward to continuing to work with you and your staff on
this and other programs in the consultative phase of the ozone
attainment efforts.
Sincerely,
S. Seitz
Director
Office of Air Quality Planning
and Standards
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TECHNICAL REPORT DATA
(Please read Instructions on reverse before completing)
I. REPORT HO.
EPA-452/R-96-005
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
NOx Policy Documents for The Clean Air Act of
1990
5. REPORT DATE
March 1996
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Ted Creekmore
Ozone Policy and Strategies Group
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
U.S. Environmental Protection Agency
Office of Air Quality Planning and
Standards
Research Triangle Park, NC 27711
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Director
Office of Air Quality Planning and
Standards
Office of Air and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/200/04
IS. SUPPLEMENTARY NOTES
16. ABSTRACT
Copies of several guidelines and policy memorandum which EPA wrote to
explain NOx policy in the Clean Air Act.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
c. COSATI
Field/Group
NOx Guidance, NOx RACT,
NOx Substitution
Air Pollution control
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS ^Report)
Unclassified
21. NO. OF PAGES
164
2O. SECURITY CLASS (Page ~i
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77)
PREVIOUS EDITION IS OBSOLETE
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