[Federal Register Volume 69, Number 126 (Thursday, July 1, 2004)]
[Rules and Regulations]
[Pages 40004-40081]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-14213]



[[Page 40003]]

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Part II





Environmental Protection Agency





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40 CFR Part 93



Transportation Conformity Rule Amendments for the New 8-hour Ozone and 
PM2.5 National Ambient Air Quality Standards and Miscellaneous 
Revisions for Existing Areas; Transportation Conformity Rule 
Amendments: Response to Court Decision and Additional Rule Changes; 
Final Rule

  Federal Register / Vol. 69, No. 126 / Thursday, July 1, 2004 / Rules 
and Regulations  

[[Page 40004]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 93

[FRL-7774-6]
RIN 2060-AL73; 2060-AI56


Transportation Conformity Rule Amendments for the New 8-hour 
Ozone and PM2.5 National Ambient Air Quality Standards and 
Miscellaneous Revisions for Existing Areas; Transportation Conformity 
Rule Amendments: Response to Court Decision and Additional Rule Changes

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Today we (EPA) are amending the transportation conformity rule 
to finalize several provisions that were proposed last year. First, 
today's final rule includes criteria and procedures for the new 8-hour 
ozone and fine particulate matter (PM2.5) national ambient 
air quality standards (NAAQS or ``standards''). Transportation 
conformity is required under Clean Air Act section 176(c) to ensure 
that federally supported highway and transit project activities are 
consistent with (``conform to'') the purpose of a state air quality 
implementation plan (SIP). We are conducting this rulemaking in part to 
revise the conformity regulation in the context of EPA's broader 
strategies for implementing the new ozone and PM2.5 
standards.
    The final rule also addresses a March 2, 1999 ruling by the U.S. 
Court of Appeals for the District of Columbia Circuit (Environmental 
Defense Fund v. EPA, et al., 167 F. 3d 641, D.C. Cir. 1999). This final 
rule incorporates into the transportation conformity rule the EPA and 
Department of Transportation (DOT) guidance that has been used in place 
of certain regulatory provisions of the rule since the court decision.
    DOT is EPA's federal partner in implementing the transportation 
conformity regulation. We have consulted with DOT on the development of 
this rulemaking, and DOT concurs with this final rule.
    EPA notes that a supplemental notice of proposed rulemaking will be 
published in the near future to request additional comment on options 
related to PM2.5 and PM10 hot-spot requirements. 
EPA is also not finalizing at this time any requirements for addressing 
PM2.5 precursors in transportation conformity determinations 
for PM2.5 nonattainment and maintenance areas. EPA is 
considering the transportation conformity rule's PM2.5 
precursor requirements in the context of EPA's broader PM2.5 
implementation strategy. All of these issues will be addressed in a 
separate final rule to be issued before PM2.5 designations 
become effective.

EFFECTIVE DATE: August 2, 2004.

ADDRESSES: Materials relevant to this rulemaking for the November 5, 
2003 proposal (68 FR 62690) are in Public Docket I.D. No. OAR-2003-
0049. Materials relevant to this rulemaking for the June 30, 2003 
proposal (68 FR 38974) are in Public Docket I.D. No. OAR-2003-0063. For 
more information about accessing information from the docket, see 
Section I.B. of the SUPPLEMENTARY INFORMATION section.

FOR FURTHER INFORMATION CONTACT: Meg Patulski, State Measures and 
Conformity Group, Transportation and Regional Programs Division, U.S. 
Environmental Protection Agency, 2000 Traverwood Road, Ann Arbor, MI 
48105, [email protected], (734) 214-4842; Rudy Kapichak, State 
Measures and Conformity Group, Transportation and Regional Programs 
Division, U.S. Environmental Protection Agency, 2000 Traverwood Road, 
Ann Arbor, MI 48105, [email protected], (734) 214-4574; or Laura 
Berry, State Measures and Conformity Group, Transportation and Regional 
Programs Division, U.S. Environmental Protection Agency, 2000 
Traverwood Road, Ann Arbor, MI 48105, [email protected], (734) 214-
4858.

SUPPLEMENTARY INFORMATION:
    The contents of this preamble are listed in the following outline:

I. General Information
I. Background on the Transportation Conformity Rule
II. Conformity Grace Period and Revocation of the 1-hour Ozone 
Standard
III. General Changes in Interim Emissions Tests
IV. Regional Conformity Tests in 8-hour Ozone Areas That Do Not Have 
1-hour Ozone SIPs
V. Regional Conformity Tests in 8-hour Ozone Areas That Have 1-hour 
Ozone SIPs
VI. Regional Conformity Tests in PM2.5 Areas
VIII. Consideration of Direct PM2.5 and pm2.5 
Precursors in Regional Emissions Analyses
IX. Re-entrained Road Dust in PM2.5 Regional Emissions 
Analyses
X. Construction-Related Fugitive Dust in PM2.5 Regional 
Emissions Analyses
XI. Compliance with PM2.5 SIP Control Measures
XII. PM2.5 Hot-spot Analyses
XIII. PM10 Hot-spot Analyses
XIV. Federal Projects
XV. Using Motor Vehicle Emissions Budgets from Submitted SIPs for 
Transportation Conformity Determinations
XVI. Non-federal Projects
XVII. Conformity Consequences of Certain SIP Disapprovals
XVIII. Safety Margins
XIX. Streamlining the Frequency of Conformity Determinations
XX. Latest Planning Assumptions
XXI. Horizon Years for Hot-spot Analyses
XXII. Relying on a Previous Regional Emissions Analysis
XXIII. Miscellaneous Revisions
XXIV. Comments Not Related to Rulemaking
XXV. How Does Today's Final Rule Affect Conformity SIPs?
XXVI. Statutory and Executive Order Reviews

I. General Information

A. Regulated Entities

    Entities potentially regulated by the conformity rule are those 
that adopt, approve, or fund transportation plans, programs, or 
projects under title 23 U.S.C. or title 49 U.S.C. Regulated categories 
and entities affected by today's action include:

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                                                Examples of regulated
                 Category                             entities
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Local government..........................  Local transportation and air
                                             quality agencies, including
                                             metropolitan planning
                                             organizations (MPOs).
State government..........................  State transportation and air
                                             quality agencies.
Federal government........................  Department of Transportation
                                             (Federal Highway
                                             Administration (FHWA) and
                                             Federal Transit
                                             Administration (FTA)).
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    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by this 
final rule. This table lists the types of entities of which EPA is 
aware that potentially could be regulated by the conformity rule. Other 
types of entities not listed in the table could also be regulated. To 
determine whether your organization is regulated by this action, you 
should carefully examine the applicability requirements in Sec.  93.102 
of the transportation conformity rule. If you have questions regarding 
the applicability of this action to a particular entity, consult the 
persons listed in the preceding FOR FURTHER INFORMATION CONTACT 
section.

B. How Can I Get Copies of This Document?

    1. Docket. EPA has established official public dockets for today's 
final rule. Materials relevant to this rulemaking for the November 5, 
2003 proposal (68 FR 62690) are in Public Docket I.D. No. OAR-2003-
0049. Materials relevant to this rulemaking for the June 30, 2003 
proposal (68 FR 38974) are in Public Docket I.D. No. OAR-2003-0063. The

[[Page 40005]]

official public docket consists of the documents specifically 
referenced in this action, any public comments received, and other 
information related to this action. Although a part of the official 
docket, the public docket does not include Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. The official public docket is the collection of materials 
that is available for public viewing at the Air Docket in the EPA 
Docket Center, (EPA/DC) EPA West, Room B102, 1301 Constitution Ave., 
NW, Washington, DC. The Docket telephone number is (202) 566-1742. The 
EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744. You may have to 
pay a reasonable fee for copying docket materials.
    2. Electronic Access. You may access this Federal Register document 
electronically through EPA's transportation conformity Web site at 
http://www.epa.gov/otaq/transp/traqconf.htm. You may also access this 
document electronically under the Federal Register listings at http://www.epa.gov/fedrgstr/.
    An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA Dockets. You may 
use EPA Dockets at http://www.epa.gov/edocket/ to view public comments, 
access the index listing of the contents of the official public docket, 
and to access those documents in the public docket that are available 
electronically. Although not all docket materials may be available 
electronically, you may still access any of the publicly available 
docket materials through the docket facility identified in Section 
I.B.1. Once in the EPA electronic docket system, select ``search,'' 
then key in the appropriate docket identification number.

II. Background on the Transportation Conformity Rule

A. What Is Transportation Conformity?

    Transportation conformity is required under Clean Air Act section 
176(c) (42 U.S.C. 7506(c)) to ensure that federally supported highway 
and transit project activities are consistent with (``conform to'') the 
purpose of the state air quality implementation plan (SIP). Conformity 
currently applies under EPA's rules to areas that are designated 
nonattainment, and those redesignated to attainment after 1990 
(``maintenance areas'' with plans developed under Clean Air Act section 
175A) for the criteria pollutants: ozone, particulate matter with an 
aerodynamic diameter less than or equal to a nominal 10 micrometers 
(PM10), carbon monoxide (CO), and nitrogen dioxide 
(NO2). Today's final rule also applies the conformity rule 
provisions in fine particulate matter (PM2.5) areas. 
Conformity to the purpose of the SIP means that transportation 
activities will not cause new air quality violations, worsen existing 
violations, or delay timely attainment of the relevant national ambient 
air quality standards (NAAQS or ``standards''). EPA's transportation 
conformity rule establishes the criteria and procedures for determining 
whether transportation activities conform to the SIP.
    EPA first promulgated the transportation conformity rule on 
November 24, 1993 (58 FR 62188), and subsequently published a 
comprehensive set of amendments on August 15, 1997 (62 FR 43780) that 
clarified and streamlined language from the 1993 rule. EPA has made 
other smaller amendments to the rule both before and after the 1997 
amendments.
    Today's final rule includes provisions from two proposals that were 
published on June 30, 2003 and November 5, 2003, as described below. 
EPA has consulted with the Department of Transportation (DOT), our 
federal partner in implementing the transportation conformity 
regulation, in developing all aspects of this rulemaking, and DOT 
concurs with this final rule.

B. What Did EPA Propose on June 30, 2003 and Why?

    Today's final rule incorporates existing federal guidance into the 
conformity regulation consistent with a previous court decision. A 
decision made on March 2, 1999, by the U.S. Court of Appeals for the 
District of Columbia Circuit affected several provisions of the August 
15, 1997 rulemaking (Environmental Defense Fund v. EPA, et al., 167 F. 
3d 641, D.C. Cir. 1999; hereinafter referred to as the ``court 
decision''). Specifically, the court's ruling affected provisions that 
pertain to five aspects of the conformity rule, including:
    (1) Federal approval and funding of transportation projects in 
areas without a currently conforming transportation plan and 
transportation improvement program (TIP);
    (2) Provisions allowing motor vehicle emissions budgets from 
submitted SIPs to be used in transportation conformity determinations 
before the SIP has been approved;
    (3) The adoption and approval of non-federal transportation 
projects in areas without a currently conforming transportation plan 
and TIP;
    (4) The timing of conformity consequences following an EPA 
disapproval of a control strategy SIP (e.g., reasonable further 
progress SIPs and attainment demonstrations) without a protective 
finding; and,
    (5) The use of submitted safety margins in areas with approved SIPs 
that were submitted prior to November 24, 1993.
    In response to the court decision, the EPA and DOT issued guidance 
\1\ to address the provisions directly affected by the court decision. 
DOT also issued guidance on May 20, 2003, to clarify the conformity 
requirements as they relate to FHWA/FTA projects that require 
environmental impact statements.\2\ In addition, FTA issued guidance on 
April 9, 2003, that further clarified which approvals are necessary for 
transit projects to proceed during a conformity lapse.\3\ EPA and DOT 
consulted on the development of all of the guidance documents that were 
issued to implement the court decision.
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    \1\ May 14, 1999, Memorandum from Gay MacGregor, then-Director 
of the Regional and State Programs Division of EPA's Office of 
Transportation and Air Quality, to Regional Air Division Directors, 
``Conformity Guidance on Implementation of March 2, 1999, Conformity 
Court Decision''; January 2, 2002, Memorandum from Mary E. Peters, 
Administrator, Federal Highway Administration (FHWA), and Jennifer 
L. Dorn, Administrator, Federal Transit Administration (FTA), to 
FHWA Division Administrators, Federal Lands Highway Division 
Engineers, and FTA Regional Administrators, ``Revised Guidance for 
Implementing the March 1999 Circuit Court Decision Affecting 
Transportation Conformity''; February 7, 2002, Notice, Issuance of 
Revised Guidance for Implementing the March 1999 Circuit Court 
Decision Affecting Transportation Conformity, Federal Register, 67 
FR 5882.
    \2\ May 20, 2003, Memorandum from James M. Shrouds, Director, 
Office of Natural and Human Environment, FHWA, and Susan Borinsky, 
Director, Office of Human and Natural Environment, FTA, to FHWA 
Division Administrators, Federal Lands Highway Division Engineers, 
and FTA Regional Administrators, ``INFORMATION: Clarification of 
Transportation Conformity Requirements for FHWA/FTA Projects 
Requiring Environmental Impact Statements.''
    \3\ April 9, 2003, Memorandum from Jennifer L. Dorn, 
Administrator, FTA, to Regional Administrators, Regions 1-10, 
``INFORMATION: Revised FTA Procedures for a Conformity Lapse.''
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    This final rule incorporates all of these guidance documents, as 
proposed in EPA's June 30, 2003 rulemaking entitled, ``Transportation 
Conformity Rule Amendments: Response to Court Decision and Additional 
Rule Changes'' (68 FR 38974). EPA notes that although guidance 
implementing the court decision will still apply upon the effective 
date of this final rule, aspects of these guidance documents that are 
specifically addressed in this rulemaking will be governed by the

[[Page 40006]]

federal conformity rules when they become effective. In addition to 
issues affected by the court, the June 30, 2003 proposal and today's 
final rule include several amendments to other provisions of the 
conformity regulations. These amendments are aimed at improving the 
implementation of the conformity program.
    The June 30, 2003 proposal and the comments received on that 
proposal serve as the basis for related provisions of today's final 
rule. The public comment period for the proposed rule ended on July 30, 
2003. EPA received 25 sets of public comments on the proposed rule from 
MPOs; state and local transportation and air quality agencies; and, 
environmental, transportation and construction industry advocacy 
groups. Today's final rule makes several minor changes to the June 30, 
2003 proposed rule in response to these stakeholder comments. The 
changes from the June 30, 2003 proposal and EPA's rationale for these 
changes are stated below. EPA has not, however, restated in this final 
rule background information and our complete rationale for many of the 
revisions to the conformity rule that are identical to the June 2003 
proposal. The reader is referred to the proposal for such discussions. 
A copy of the proposal can be downloaded from EPA's transportation 
conformity website listed in Section I.B.2. of today's rulemaking.

C. What Did EPA Propose on November 5, 2003 and Why?

    This final rule is also based on the November 5, 2003 proposed rule 
entitled, ``Transportation Conformity Rule Amendments for the New 8-
Hour Ozone and PM2.5 National Ambient Air Quality Standards 
and Miscellaneous Revisions for Existing Areas'' (68 FR 62690), and the 
comments received on that proposal. The public comment period for this 
proposal ended on December 22, 2003. EPA held one public hearing for 
this proposal on December 4, 2003. EPA received over 110 sets of public 
comments on the proposed rule from MPOs, state and local transportation 
and air quality agencies, and environmental and transportation advocacy 
groups. EPA also received over 11,000 similar comments on the proposal 
from public citizens from a mass e-mail campaign. Today's final rule 
promulgates proposed options and rule revisions in response to these 
stakeholder comments. This preamble explains EPA's rationale for the 
selection of certain proposed options described in the November 2003 
proposal. A copy of the November 2003 proposal can be downloaded from 
EPA's transportation conformity website listed in Section I.B.2. of 
today's rulemaking.
    EPA's nonattainment area designations for the new 8-hour ozone 
standard are effective on June 15, 2004 for most areas, and EPA 
anticipates designating areas for the new PM2.5 air quality 
standard in November or December 2004. EPA is conducting this 
rulemaking to provide clear guidance and rules for implementing 
conformity for these standards. Some of the conformity rule revisions 
in this rulemaking will provide more options and flexibility in 
demonstrating conformity. Other changes apply to existing 1-hour ozone, 
CO, PM10 and NO2 nonattainment and maintenance 
areas.
    EPA notes that today's action does not finalize new transportation 
conformity requirements for PM2.5 precursors and 
PM2.5 hot-spot analyses, or make changes to existing 
PM10 hot-spot analysis requirements. EPA is considering 
requirements for addressing PM2.5 precursors in 
transportation conformity determinations in the context of EPA's 
broader PM2.5 implementation strategy. EPA will soon be 
publishing a supplemental notice of proposed rulemaking to request 
additional comment on options related to PM2.5 and 
PM10 hot-spot requirements. PM2.5 precursors and 
PM2.5/PM10 hot-spot analysis requirements will be 
addressed in a separate final rule to be issued before PM2.5 
designations become effective. See Sections VIII., XII., and XIII. for 
further information on these topics.
    Other changes to the conformity program could occur in the future 
through the reauthorization of the Transportation Equity Act for the 
21st Century (TEA-21), which authorizes federal surface transportation 
programs. EPA will continue to monitor the proposed reauthorization 
proposals for their potential impact on the conformity regulation. If 
statutory amendments to the conformity program result from TEA-21 
reauthorization, EPA would take appropriate action to address such 
changes in the future.

D. What Parts of the Final Rule Apply to Me?

    The following table provides a roadmap for determining whether a 
specific final rule revision included in this rulemaking would apply in 
your area. This table illustrates which parts of the final rule are 
relevant for various pollutants and standards. Please note that 
Sections V.-VII. provide stand-alone descriptions of the regional 
emissions tests that will apply in PM2.5 areas and 8-hour 
ozone areas with and without existing 1-hour ozone SIPs. For example, 
if your area expects only to be designated nonattainment under the 
PM2.5 standard, you should read Section VII. but not 
Sections V. and VI. (for 8-hour ozone areas). EPA believes that any 
redundancy between these sections is warranted to assist readers that 
may not need to read the entire final rule.\4\
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    \4\ ``Subpart 1 areas'' are areas that are designated 
nonattainment under subpart 1 of part D of title 1 of the Clean Air 
Act. EPA also referred to these areas as ``basic'' nonattainment 
areas in its April 30, 2004 final designations rule for the 8-hour 
ozone standard (69 FR 23862).

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                               Issue addressed in final
        Type of area                     rule               Preamble section           Regulatory section
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8-hour ozone...............  Conformity grace period....  III.A.                Sec.   93.102(d).
                             Revocation of 1-hour ozone   III.B.                Not applicable.
                              standard.
                             General implementation of    III.C.                Not applicable.
                              new standards.
                             Early Action Compacts......  III.D.                Not applicable.
                             Baseline year test.........  IV.B.                 Sec.   93.119(b).
                             Build/no-build test          IV.C.                 Sec.   93.119(b)(2); Sec.
                              (marginal classification                           93.119(g)(2).
                              and subpart 1 areas \4\).
                             Regional conformity tests    IV.D.                 Sec.   93.119(b)(1).
                              (moderate and above
                              classifications).
                             Regional conformity tests    V.                    Sec.   93.109(d).
                              (areas without 1-hour
                              ozone budgets).
                             Regional conformity tests    VI.                   Sec.   93.109(e).
                              (areas with 1-hour ozone
                              budgets).
                             Definitions................  XIV.A.                Sec.   93.101.
                             Insignificance.............  XIV.B.                Sec.   93.109(k); Sec.
                                                                                 93.121(c).

[[Page 40007]]

 
                             Transportation plan and      XIV.D.                Sec.   93.106(b); Sec.
                              modeling requirements                              93.122(c).
                              (moderate and above
                              classifications).
                             Non-federal projects (for    XIV.F.                Sec.   93.121(b)(1).
                              isolated rural areas only).
PM2.5......................  Applicability..............  III.A.                Sec.   93.102(b)(1).
                             Conformity grace period....  III.A.                Sec.   93.102(d).
                             Baseline year test.........  IV.B.                 Sec.   93.119(e).
                             Build/no-build test........  IV.C.                 Sec.   93.119(e); Sec.
                                                                                 93.119(g)(2).
                             Regional conformity tests..  VII.                  Sec.   93.109(i).
                             Precursors in regional       VIII.                 No regulatory text being
                              analyses.                                          finalized.
                             Re-entrained road dust in    IX.                   Sec.   93.102(b)(3); Sec.
                              regional analyses.                                 93.119(f).
                             Construction-related         X.                    Sec.   93.122(f).
                              fugitive dust in regional
                              analyses.
                             Compliance with SIP control  XI.                   Sec.   93.117.
                              measures.
                             Hot-spots..................  XII.                  No regulatory text being
                                                                                 finalized.
                             Definitions................  XIV.A.                Sec.   93.101.
                             Insignificance.............  XIV.B.                Sec.   93.109(k); Sec.
                                                                                 93.121(c).
                             Non-federal projects (for    XIV.F.                Sec.   93.121(b)(1).
                              isolated rural areas only).
1-hour ozone...............  Revocation of 1-hour ozone   III.B.                No proposed regulatory
                              standard.                                          amendments.
                             Build/no-build test          IV.C.                 Sec.   93.119(b)(2); Sec.
                              (marginal and below                                93.119(g)(2).
                              classifications).
                             Regional conformity tests    IV.D.                 Sec.   93.119(b)(1).
                              (moderate and above
                              classifications).
                             Definitions................  XIV.A.                Sec.   93.101.
                             Insignificance.............  XIV.B.                Sec.   93.109(k); Sec.
                                                                                 93.121(c).
                             Limited maintenance plans..  XIV.C.                Sec.   93.101; Sec.   93.109(j);
                                                                                 Sec.   93.121(c).
                             Transportation plan and      XIV.D.                Sec.   93.106(b); Sec.
                              modeling requirements                              93.122(c).
                              (moderate and above
                              classifications).
                             Non-federal projects (for    XIV.F.                Sec.   93.121(b)(1).
                              isolated rural areas only).
                             Clarification to use of      XIV.G.                Sec.   93.109(c).
                              approved budgets in
                              conformity.
PM10.......................  Build/no-build test........  IV.C.                 Sec.   93.119(d); Sec.
                                                                                 93.119(g)(2).
                             Compliance with SIP control  XI.                   No proposed regulatory
                              measures (Request for                              amendments.
                              information only).
                             Hot-spots..................  XIII.                 No regulatory text being
                                                                                 finalized.
                             Clarification to Precursors  XIV.E.                Sec.   93.102(b)(2); Sec.
                                                                                 93.119(f)(5).
                             Definitions................  XIV.A.                Sec.   93.101.
                             Insignificance.............  XIV.B.                Sec.   93.109(k); Sec.
                                                                                 93.121(c).
                             Limited maintenance plans..  XIV.C.                Sec.   93.101; Sec.   93.109(j);
                                                                                 Sec.   93.121(c).
                             Non-federal projects (for    XIV.F.                Sec.   93.121(b)(1).
                              isolated rural areas only).
                             Clarification to use of      XIV.G.                Sec.   93.109(g).
                              approved budgets in
                              conformity.
CO.........................  Build/no-build test (lower   IV.C.                 Sec.   93.119(c); Sec.
                              CO classifications).                               93.119(g)(2).
                             Regional conformity tests    IV.D.                 Sec.   93.119(c)(1).
                              (higher CO
                              classifications).
                             Definitions................  XIV.A.                Sec.   93.101.
                             Insignificance.............  XIV.B.                Sec.   93.109(k); Sec.
                                                                                 93.121(c).
                             Limited maintenance plans..  XIV.C.                Sec.   93.101; Sec.   93.109(j);
                                                                                 Sec.   93.121(c).
                             Transportation plan and      XIV.D.                Sec.   93.106(b); Sec.
                              modeling requirements                              93.122(c).
                              (moderate and serious
                              classifications).
                             Non-federal projects (for    XIV.F.                Sec.   93.121(b)(1).
                              isolated rural areas only).
                             Clarification to use of      XIV.G.                Sec.   93.109(f).
                              approved budgets in
                              conformity.
NO2........................  Build/no-build test........  IV.C.                 Sec.   93.119(d); Sec.
                                                                                 93.119(g)(2).
                             Definitions................  XIV.A.                Sec.   93.101.
                             Insignificance.............  XIV.B.                Sec.   93.109(k); Sec.
                                                                                 93.121(c).
                             Non-federal projects (for    XIV.F.                Sec.   93.121(b)(1).
                              isolated rural areas only).
                             Clarification to use of      XIV.G.                Sec.   93.109(h).
                              approved budgets in
                              conformity.
----------------------------------------------------------------------------------------------------------------


[[Page 40008]]

E. Does This Final Rule Include the Entire Transportation Conformity 
Regulation?

    No. The regulatory text in this final rule is limited to changes to 
affected portions of the conformity rule. However, a complete version 
of the conformity rule is available to the public on our transportation 
conformity website listed in Section I.B.2. of this rulemaking. The 
complete version is intended to help reviewers understand today's final 
rule in context with other existing rule sections that are not being 
changed.

III. Conformity Grace Period and Revocation of the 1-hour Ozone 
Standard

A. When Will Conformity Apply for the 8-hour Ozone and PM2.5 
Standards?

1. Description of Final Rule
    Conformity applies one year after the effective date of EPA's 
initial nonattainment designation for a given pollutant and standard. 
This one-year conformity grace period is provided by Clean Air Act 
section 176(c)(6) and Sec.  93.102(d) of the conformity regulation. 
This final rule adds PM2.5 to Sec.  93.102(d) of the 
conformity rule even though the grace period is already available to 
all newly designated nonattainment areas as a matter of law.
    Since the 1-hour and 8-hour ozone standards are different NAAQS, 
every area that was designated nonattainment for the 8-hour ozone 
standard has a one-year grace period before conformity applies for that 
standard even if the area was previously designated nonattainment for 
the 1-hour ozone standard. Areas subject to conformity for the 1-hour 
ozone standard continue to be subject to all applicable Clean Air Act 
requirements during the 1-year conformity grace period for the 8-hour 
ozone standard, as described in B. of this section. EPA designated 
areas for the 8-hour ozone standard on April 15, 2004, and published 
the final designations rule on April 30, 2004 (69 FR 23858). 
Designations for most of these 8-hour areas will be effective on June 
15, 2004. Therefore, conformity for the 8-hour ozone standard will 
begin to apply on June 15, 2005 in most areas.
    When conformity is done for the 1-hour standard during the grace 
period for the 8-hour standard, areas should consider whether 
demonstrating conformity for the 1-hour and 8-hour ozone standards at 
the same time is possible or advantageous. For example, if a conformity 
determination is made in September 2004 for a new or revised 
transportation plan and/or TIP, an area would demonstrate conformity 
for the 1-hour ozone standard and may choose to address the 8-hour 
ozone standard at a later date near the end of the one-year grace 
period, if conformity analyses for the 8-hour standard are not yet 
completed. In contrast, if a conformity determination is made in 
January 2005 for a new or revised plan/TIP, an area may be able to 
complete all the necessary work to demonstrate conformity for both 
ozone standards at that time. If no new or revised plan/TIP is required 
during the one-year grace period, conformity could be determined for 
the 8-hour standard without also making a conformity determination for 
the 1-hour standard. Whatever the case, a conformity determination for 
the 8-hour standard must be in place on June 15, 2005 for the plan and 
TIP, or an area will lapse.
    Areas should use the interagency consultation process to determine 
a schedule for conducting regional emissions analyses and demonstrating 
conformity for the 1-hour and 8-hour ozone standards during the one-
year conformity grace period as appropriate. Areas can rely on similar 
analyses and other work for conformity determinations for existing and 
new standards, to the extent that such work meets applicable 
requirements.
    EPA plans to designate areas for PM2.5 by November or 
December of 2004. Similarly, every area that is designated 
nonattainment for the PM2.5 standard will have a one-year 
grace period from the effective date of designations before conformity 
applies for that standard. It is important to note that PM10 
is a different pollutant than PM2.5, and today's final rule 
does not affect the applicability and continued general implementation 
of conformity in PM10 nonattainment and maintenance areas.
    EPA anticipates that some areas will be designated as nonattainment 
for both the 8-hour ozone and PM2.5 standards. In these 
areas, conformity for the 8-hour ozone standard will apply one year 
after the effective date of the area's 8-hour ozone designation, while 
conformity for PM2.5 will apply one year after the effective 
date of the area's PM2.5 designation.
    As described in the November 5, 2003 proposal, if upon the 
expiration of the one-year grace period, a metropolitan area does not 
have a transportation plan and TIP that conform to the applicable 
standard in place, the conformity status of the area ``lapses.'' 
Likewise, within one year after the effective date of an area's initial 
nonattainment designation, the existing and planned transportation 
network for any donut \5\ portion of an area (as well as for the 
metropolitan portion of the area) must demonstrate conformity, or 
conformity of the metropolitan transportation plan and TIP will lapse, 
and the entire nonattainment area will be unable to obtain additional 
non-exempt project funding and approvals at that time. During a 
conformity lapse funding and approval of transportation projects are 
restricted and only limited types of projects can proceed (e.g., safety 
projects, project phases that were approved before the lapse).
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    \5\ As defined in Sec.  93.101 of today's final rule, donut 
areas are geographic areas outside a metropolitan planning area 
boundary, but inside the boundary of a nonattainment or maintenance 
area that contains any part of a metropolitan area(s). These areas 
are not isolated rural nonattainment and maintenance areas.
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    The November 2003 proposal also stated that the one-year conformity 
grace period applies in isolated rural nonattainment areas.\6\ However, 
conformity determinations in isolated rural areas are required only 
when a non-exempt FHWA/FTA project needs funding or approval. 
Therefore, once the conformity grace period has expired, a conformity 
determination will only be required in such areas the next time a non-
exempt project needs funding or approval.
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    \6\ As defined in Sec.  93.101 of today's final rule, isolated 
rural nonattainment and maintenance areas are areas that do not 
contain or are not part of any metropolitan planning area as 
designated under the transportation planning regulations. These 
areas are not donut areas.
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    For more information on the application of the conformity grace 
period in metropolitan, donut and isolated rural nonattainment areas, 
see the November 5, 2003 proposal to this final rule (68 FR 62695-
62696). See Section III.C. below for guidance and EPA's responses to 
comments regarding implementation of the one-year grace period and 
conformity determinations under the new standards.

2. Rationale and Response to Comments

    EPA received a number of comments on the one-year conformity grace 
period and the transition from the 1-hour ozone standard to the 8-hour 
ozone standard. Most commenters supported the one-year conformity grace 
period, with some commenters stating that the grace period makes sense 
and will provide state and local agencies with the time needed to 
prepare for conformity under the new standards. Another commenter 
supported the grace period as a means to prevent having to demonstrate 
conformity to two ozone standards simultaneously.

[[Page 40009]]

    Some commenters, however, believed that the one-year grace period 
would not allow enough time for some areas to meet the conformity 
requirements. One of these commenters questioned whether a year would 
be enough time to implement the interagency consultation process in 
brand new nonattainment areas or in existing nonattainment and 
maintenance areas that change in size or complexity. A few other 
commenters argued that the one-year grace period does not provide 
adequate time for new MPOs to become familiar with the conformity 
process or for existing MPOs to complete technical documentation and 
the public and adoption processes in nonattainment counties that are 
not within the MPO's jurisdiction (i.e., donut areas).
    To address these concerns, a few commenters suggested approaches 
for lengthening the conformity grace period. One commenter that was 
concerned about the lack of experience and resource burden on new and 
rural nonattainment areas requested that the grace period be extended 
to two years for these areas. Another commenter suggested that EPA 
provide a longer 60-day effective date for nonattainment designations, 
effectively giving areas two additional months before the conformity 
requirements apply.
    EPA understands that some areas, including brand new metropolitan 
areas, donut areas, and complex nonattainment areas (e.g., areas with 
multiple states and/or multiple MPOs) may have additional challenges in 
conducting the conformity process. However, the Clean Air Act, as 
amended on October 27, 2000, specifically provides newly designated 
nonattainment areas with only a one-year grace period, after which 
conformity applies as a matter of law under the statute. Therefore, we 
believe that the statutory language precludes EPA from extending the 
conformity grace period beyond one year for new nonattainment areas. We 
emphasize, however, that EPA issued letters to the states effectively 
notifying areas of their proposed 8-hour ozone nonattainment 
designation in December 2003 and that states submitted their 
recommendations for nonattainment areas based on monitored data, well 
before designations became effective.\7\ In addition, state and local 
agencies of potential nonattainment areas have been involved early on 
in the 8-hour designation process. These new ozone nonattainment areas 
have already had additional time ahead of the one-year grace period to 
begin developing consultation procedures, modeling tools and data 
collections efforts for implementing the conformity regulation. EPA 
anticipates that areas designated nonattainment under the 
PM2.5 standard will have similar advance notice of their 
pending designations, since state recommendations were due February 15, 
2004, and many areas already expect that they will be designated 
nonattainment for PM2.5.
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    \7\ Information on 8-hour ozone nonattainment designations, 
including copies of EPA's December 2003 designation letters, can be 
accessed from EPA's Web site at http://www.epa.gov/air/oaqps/glo/designations/index.htm.
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    The amount of time between the publication and effective dates of 
an action is established by EPA on a case-by-case basis for each 
rulemaking. We generally believe that the time needed for states to 
implement obligations for the NAAQS is fully considered in the 
statutory or regulatory provision establishing the compliance timeframe 
and that the effective date of the designations should not be used as a 
method for adjusting the compliance timeframes. In the context of 
promulgating the 8-hour ozone designations, EPA determined that it was 
appropriate to make the designations effective on June 15, 2004, 
approximately 45 days following the publication date of the 
designations. EPA will consider the appropriate effective date for 
PM2.5 designations at the time it promulgates those 
designations.
    EPA notes that Section III.C. of today's final rule includes 
guidance on general and specific questions raised by commenters for 
implementing the new standards. In addition, EPA will release guidance 
on specific implementation issues that may arise in some of the 
different types of new nonattainment areas (e.g., multi-state and/or 
multiple MPO areas). We will provide this information in response to 
requests for clarification raised during the public comment period for 
this rulemaking. Newly designated nonattainment areas should also 
consult with their respective EPA regional and DOT division offices for 
additional guidance and assistance in meeting the conformity 
requirements within the one-year grace period. In addition, EPA and DOT 
will be conducting training sessions for the new standards conformity 
rulemaking in the near future that state and local agencies can attend; 
areas can also take advantage of existing EPA and DOT conformity \8\ 
and emissions modeling \9\ training that is currently available.
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    \8\ The National Transit Institute offers a course entitled, 
``Introduction to Transportation/Air Quality Conformity.'' This 
course was developed by FTA, FHWA and EPA and is designed for 
federal, state and local agencies involved in the conformity 
process. In addition, the National Highway Institute offers a course 
entitled, ``Estimating Regional Mobile Source Emissions.''
    \9\ EPA and DOT jointly sponsored seven MOBILE6 training courses 
across the country in 2002. The training materials for these courses 
are on EPA's MOBILE6 website and can be downloaded at: http://www.epa.gov/otaq/m6.htm. Other training materials prepared by EPA 
are also available on this website.
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B. When Does Conformity Stop Applying for the 1-hour Ozone Standard?

1. Description of Final Rule
    Conformity for the 1-hour ozone standard will no longer apply in 
existing 1-hour ozone nonattainment and maintenance areas once that 
standard and corresponding designations are revoked. Today's final 
conformity rule and responses to comments with respect to this issue 
are consistent with EPA's April 30, 2004, 8-hour ozone implementation 
final rule that revokes the 1-hour standard one year after the 
effective date of EPA's 8-hour designations (69 FR 23951).
    Current 1-hour nonattainment and maintenance areas will continue to 
ensure that transportation activities conform to the existing 1-hour 
standard, including any applicable existing adequate or approved 1-hour 
SIP budgets, until that standard is revoked. When the 1-hour standard 
is revoked, conformity will no longer apply for either ozone standard 
in areas that are attaining the 8-hour ozone standard. Section 
93.109(c) of today's final rule addresses conformity requirements for 
the 1-hour ozone standard. See EPA's April 30, 2004, 8-hour 
implementation final rule for more discussion on the revocation of the 
1-hour ozone standard (69 FR 23951).
2. Rationale and Response to Comments
    Many commenters supported the revocation of the 1-hour ozone 
standard at the time conformity applies for the 8-hour ozone standard. 
Several commenters believed that requiring conformity for both ozone 
standards at the same time would be overly burdensome and confusing, 
and would significantly impact state and local resources and the 
transportation sector. These commenters supported a final rule that 
focused on attainment of the 8-hour standard, rather than created 
duplicative conformity requirements for two ozone standards. One 
commenter also argued that requiring conformity for both ozone 
standards at the same time could undermine progress to achieve

[[Page 40010]]

adequate emission reductions, since new nonattainment areas may have to 
develop different control strategies for attaining the 8-hour ozone 
standard. This commenter believed that such a result could leave 
nonattainment areas extremely vulnerable to litigation. Some commenters 
stated that EPA's proposal is logical, since the 8-hour ozone standard 
is presumably a more stringent standard than the 1-hour standard.
    However, other commenters believed EPA's proposal to revoke the 1-
hour standard is unlawful because they believed it would allow large 
increases in motor vehicle emissions and thus violate the statutory 
conformity tests. Other commenters stated that if the 1-hour standard 
was revoked, areas would no longer have to meet the SIP motor vehicle 
emissions budgets (``budgets'') established for that standard. These 
commenters were concerned that 8-hour nonattainment areas that were 
nonattainment or maintenance for the 1-hour standard would be able to 
determine conformity using less protective conformity tests, such as 
the build/no-build test, during the time period before new 8-hour SIP 
budgets are established. These commenters stated that not using 
existing 1-hour SIP budgets would lead to emissions increases that 
would later need to be offset by future controls for the 8-hour 
standard. Commenters also believed that using 1-hour ozone SIP budgets 
would support current air quality progress and ensure that attainment 
of the 8-hour standard is not delayed.
    As stated in the final 8-hour implementation rule (69 FR 23951) and 
corresponding response to comments document, EPA disagrees that 
revoking the 1-hour standard is unlawful. Congress gave EPA the 
authority to create and revise the NAAQS. In Clean Air Act section 
109(d)(1), Congress directed EPA to review the standards every five 
years and ``make such revisions in such criteria and standards and 
promulgate such new standards * * *.'' EPA interprets ``make such 
revisions in * * * standards'' to mean that EPA has the authority to 
replace one standard with another. EPA does not believe that Congress 
intended to have overlapping standards every five years for the same 
pollutant. If that were the case, states would be required to develop 
and implement a SIP for each version of the standard. Duplicating these 
efforts would waste limited resources because the goal of each standard 
is the same: to protect public health and welfare. EPA promulgated the 
8-hour standard in response to the latest data and science regarding 
ozone, and has determined that the 8-hour ozone standard is more 
protective of public health and welfare. EPA has made the decision to 
replace the 1-hour standard with the 8-hour standard, because it may be 
difficult for states to plan for both standards and because EPA 
concludes that the 8-hour standard is the more appropriate standard.
    Implicit in the authority to revise standards is the authority to 
revoke a standard. The U.S. Supreme Court's ruling (531 U.S. 547 
(2001)) in a challenge against EPA's 1997 8-hour ozone implementation 
strategy certainly did not state otherwise. EPA needs to be able to 
revoke standards so that states and areas can move on to implementing 
the new standard and not have to implement old standards in perpetuity. 
Finally, since the 8-hour standard is the more stringent of the two 
standards, EPA believes conforming to that standard will be sufficient, 
as noted by several commenters.
    As stated in the April 30, 2004 final 8-hour implementation rule 
(69 FR 23969), EPA believes it is sufficient that conformity be 
determined for one ozone standard at a time. EPA concludes that 
focusing conformity requirements on one ozone standard at a time will 
meet Clean Air Act conformity requirements and use limited state and 
local resources in an efficient manner.
    However, EPA agrees that the continued use of existing approved or 
adequate 1-hour SIP budgets is important for meeting 8-hour conformity 
requirements before new 8-hour SIPs are established. Section VI. of 
this final rule provides further information regarding conformity 
requirements and EPA's rationale for such requirements in 8-hour ozone 
areas that have existing 1-hour SIP budgets.
    One commenter supported EPA's proposal to revoke the 1-hour 
standard for areas that are found to be in attainment of the new 8-hour 
standard. Based on air quality data and significant reductions from 
federal and state measures that will continue to remain in place, this 
commenter believed that revoking the 1-hour standard in the commenter's 
specific area would not impact ozone emissions.
    However, two other commenters opposed eliminating conformity in 1-
hour ozone nonattainment and maintenance areas that were not designated 
nonattainment for the 8-hour standard. One of these commenters argued 
that conformity under the 1-hour maintenance plan helped prevent 8-hour 
violations, and urged EPA to work with these areas to find an 
acceptable mechanism to allow those areas that wish to retain 
conformity as a preventative measure. The other commenter believed that 
all areas that are covered by one of the ozone standards must continue 
or start to provide for clean air; the conformity process is a 
mechanism to accomplish this goal.
    Conformity cannot apply in 1-hour maintenance areas once the 
standard is revoked. The Clean Air Act specifically states that 
conformity applies only in ``a nonattainment area* * *'' and ``an area 
that was designated as a nonattainment area but that was later 
redesignated by the Administrator as an attainment area and that is 
required to develop a maintenance plan under section 7505a of this 
title* * *'' (42 U.S.C. 7506(5)). Clean Air Act section 176(c)(5) 
restricts conformity to nonattainment areas and areas that are required 
to submit maintenance plans under section 175A; in these areas, the 
Federal government's sovereign immunity is waived so that DOT can be 
required to make conformity determinations.\10\ However, after 
revocation of the 1-hour standard, the areas previously required to 
submit section 175A maintenance plans under the statute for the 1-hour 
standard will no longer be required to do so. Thus, conformity can no 
longer be required in 1-hour maintenance areas, since the Clean Air Act 
limits conformity to areas that are required to submit section 175A 
maintenance plans and no longer waives the Federal government's 
sovereign immunity for these areas after revocation.
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    \10\ The concept of sovereign immunity specifies that the 
federal government can only be subjected to regulation to the extent 
it voluntarily agrees to become subject. With respect to conformity, 
in the Clean Air Act, Congress has agreed that the federal 
government should be subject only one year after designation in 
areas designated nonattainment or previously designated 
nonattainment and redesignated to attainment subject to a 175A 
maintenance plan. Thus, sovereign immunity prevents the mandatory 
application of conformity requirements either prior to a year after 
designation or after revocation with respect to a given air quality 
standard.
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    EPA acknowledged in the June 2, 2003 proposed 8-hour implementation 
rule (68 FR 32818-32825) that our interpretation that conformity would 
not apply in 1-hour maintenance areas differs from the approach taken 
in 1997. In 1997, EPA interpreted revoking the 1-hour standard to mean 
that conformity would not apply for the 1-hour standard in areas that 
were nonattainment for the 1-hour standard, but that conformity would 
continue to apply for the 1-hour standard in areas with a maintenance 
plan. This interpretation led to an unfair and counter-intuitive 
result: areas that had attained the standard and had made the effort to 
establish a maintenance plan would have to continue a required

[[Page 40011]]

program, but areas that had not attained would not. EPA reconsidered 
this result and found it to be unfair and inappropriate. Further, upon 
reanalyzing Clean Air Act section 176(c)(5), this previous 
interpretation did not fit with the text of the statute.
    As stated in the April 30, 2004 final 8-hour implementation rule 
(69 FR 23987), EPA has concluded that the better interpretation of the 
statute is that conformity would not apply in 1-hour maintenance areas 
once the 1-hour standard is revoked, because maintenance areas are 
relieved of the obligation under Clean Air Act section 175A (42 U.S.C. 
7505a) to have a maintenance plan. Since these areas are no longer 
required to have a maintenance plan, conformity no longer applies for 
the 1-hour standard in these areas as a matter of law, and no waiver of 
sovereign immunity applies to allow imposition of conformity 
requirements.
    It is EPA's conclusion that areas that are in attainment for the 8-
hour standard are not subject to conformity because the statute 
explicitly limits the applicability of conformity to designated 
nonattainment and maintenance areas for a given pollutant and standard. 
EPA notes that these areas still have incentive to monitor the growth 
of emissions from the transportation sector; if these areas violate the 
8-hour standard, EPA would designate them nonattainment for the 8-hour 
standard and conformity would then apply. Although states cannot 
implement conformity for attainment areas as a matter of federal law, 
they could still work with their MPOs to estimate regional emissions 
that would be generated by the planned transportation system to see 
whether a violation could occur, and to address motor vehicle emissions 
growth. These type of state activities may be done under state law, 
when possible, or on a voluntary basis.
    One commenter suggested that the 1-hour standard should remain in 
place until the 8-hour standard is fully implemented and no longer 
subject to legal challenges to ensure that one of the ozone standards 
is implemented. The commenter believed that this approach would be 
particularly important for areas impacted by regional transport. Other 
commenters stated that the 8-hour ozone standard should be delayed if 
revocation of the 1-hour standard becomes delayed.
    EPA does not believe, however, that the current statutory and 
regulatory requirements allow us to extend conformity for the 1-hour 
standard or delay conformity for the 8-hour standard in the event of 
legal challenges, for example, as this commenter has suggested. In the 
April 30, 2004 final 8-hour ozone implementation rule, EPA specifically 
promulgated rules that will revoke the 1-hour standard one year after 
the effective date of 8-hour designations. Alternatively, Clean Air Act 
section 176(c)(6) and conformity rule Sec.  93.102(d) require 
conformity for the 8-hour standard one year after the effective date of 
ozone nonattainment designations. Therefore, conformity for the 8-hour 
standard will apply in areas designated nonattainment for that standard 
on June 15, 2005. As previously stated, EPA has no statutory authority 
to extend the one-year conformity grace period and delay the conformity 
requirements in new 8-hour nonattainment areas.
    A few commenters recommended that if 8-hour ozone SIP budgets are 
submitted and found adequate by EPA prior to revocation of the 1-hour 
standard, they should replace all prior ozone budgets, including those 
for the 1-hour standard. One commenter supported EPA's proposal to 
require that 1-hour conformity requirements be met prior to revocation, 
including adherence to the applicable 1-hour SIP budgets. Another 
commenter believed that only conformity for the 8-hour standard should 
apply once designations are made during the one-year grace period, 
rather than the 1-hour conformity requirements.
    EPA addressed this issue of revocation as part of its April 30, 
2004 final 8-hour implementation rule. EPA did not propose in its June 
2, 2003, 8-hour implementation proposal to revoke the 1-hour standard 
earlier than one year after designations, since EPA intended to align 
the revocation of the 1-hour standard with the application of 
conformity requirements for the 8-hour standard one year after the 
effective date of 8-hour nonattainment designations. Furthermore, EPA 
did not expect that areas would be able to submit an 8-hour SIP 
earlier.
    EPA continues to believe that most areas are unlikely to have 
adequate budgets that address the 8-hour standard before EPA revokes 
the 1-hour standard. Such budgets cannot stand alone but have to be 
associated with adopted control measures and demonstrations of either 
attainment or reasonable further progress, and EPA believes developing 
these SIPs will take states some time. Once the SIPs are submitted, EPA 
must find them adequate, a process which EPA intends to complete within 
90 days of receiving a SIP in most cases. It is very unlikely that 
states will be able to complete the work to submit 8-hour SIPs prior to 
one year from the effective date of 8-hour designations, and much less 
likely that states would have submitted them sufficiently in time for 
EPA to find them adequate before the 1-hour standard is revoked.
    Given these facts and the fact that EPA did not include in its June 
2003 8-hour implementation proposal an option for revoking the standard 
earlier than one year after 8-hour designations are effective, EPA did 
not provide for early revocation of the 1-hour standard, nor will EPA 
require 8-hour areas to expedite development of their 8-hour SIP for 
this purpose. As described above, the Clean Air Act provides a one-year 
grace period before conformity for the 8-hour standard applies, so EPA 
is not able to mandate 8-hour requirements sooner, as suggested by one 
commenter. Prior to the revocation of the 1-hour standard, new or 
revised transportation plans and TIPs must conform to the applicable 
SIP budgets for the 1-hour standard.
    Finally, one commenter believed that the final rule should address 
the situation where a new ozone nonattainment area can demonstrate 
conformity for the 8-hour standard during the grace period, but cannot 
for the 1-hour standard.
    EPA has concluded consistent with the April 30, 2004 final 8-hour 
ozone implementation rule and today's action, the 1-hour standard will 
remain in effect for one year following the effective date of 8-hour 
nonattainment designations. EPA believes this is appropriate since 8-
hour conformity cannot be required to apply before that time. 
Therefore, areas currently designated nonattainment or maintenance for 
the 1-hour ozone standard must demonstrate conformity for the 1-hour 
standard for any new or revised transportation plan, TIP and project 
approval during the one-year grace period for the 8-hour standard. In 
general, if an area must determine plan/TIP conformity during the grace 
period because of a required deadline and is unable to do so, the 
nonattainment or maintenance area's conformity for the 1-hour standard 
will lapse. This lapse would remain in effect until conformity for the 
1-hour standard is re-established or the 1-hour standard is revoked, 
regardless of whether the area conforms for the 8-hour standard during 
that time period. On the other hand, if an area's plan/TIP meets 
conformity for the 1-hour standard but cannot meet conformity for the 
8-hour standard during the grace period, the area would lapse when the 
one-year grace period ends, because at that point, conformity applies 
for the 8-hour standard.

[[Page 40012]]

C. How Do Areas Implement the One Year Conformity Grace Period and 
Transition From the 1-hour Ozone Standard?

    In the November 5, 2003 proposal, EPA provided details on the 
application of the one-year conformity grace period in metropolitan, 
donut, and isolated rural nonattainment areas (68 FR 62695-62696). New 
nonattainment areas should refer to A. of this section and the November 
2003 proposal for these discussions.
    EPA received several questions and comments regarding general 
implementation for the new standards. The paragraphs below include 
general information on the implementation of conformity requirements 
for:
     Initial conformity determinations in new nonattainment 
areas;
     regional emissions modeling requirements in new 
nonattainment areas;
     timely implementation of transportation control measures 
(TCMs) in approved SIPs;
     multi-jurisdictional nonattainment areas (e.g., multi-
state areas and areas with sub-area budgets); and
     donut and isolated rural areas.

Both the November 2003 proposal's preamble and our response to comments 
below are based on implementation precedent to date, and do not create 
any new conformity policy. Section VI. of today's notice provides more 
details on the use of 1-hour ozone budgets in 8-hour ozone 
nonattainment areas. EPA will post more detailed implementation 
guidance on its transportation conformity website for conformity 
determinations in new standard areas, including 8-hour ozone areas with 
1-hour SIP budgets and multi-state/multi-MPO nonattainment areas. 
Please see Section I.B.2. of this notice for information regarding 
EPA's conformity website.
1. Initial 8-hour Ozone and PM2.5 Conformity Determinations
    As described in A. of this section, areas that are designated 
nonattainment for the 8-hour ozone and/or PM2.5 standard 
must determine conformity of transportation plans and TIPs by the 
expiration of the one-year conformity grace period for a relevant 
pollutant and standard. Metropolitan and donut 8-hour ozone and 
PM2.5 nonattainment areas must complete all of the tasks 
that are required for a conformity determination (e.g., interagency 
consultation, regional emissions analyses, public participation, MPO 
and DOT conformity determinations) during the relevant grace period in 
order to avoid a conformity lapse upon the expiration of the grace 
period.\11\ Clean Air Act section 176(c)(6) specifically states that 
conformity will not apply in an area for a particular standard until 
one year after the area is designated for that standard. Thus, although 
completing conformity determinations for the new standards is not 
required prior to the end of the grace period, FHWA, FTA, and MPOs can 
choose to make determinations early for administrative purposes, when 
desired. FHWA and FTA have voluntarily agreed that they can make 
conformity determinations during the grace period even though it is not 
mandated by the Clean Air Act.
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    \11\ As described in A. of this section, isolated rural areas 
that are designated nonattainment for the 8-hour ozone and/or 
PM2.5 standard may not need to demonstrate conformity by 
the expiration of the one-year grace period. Newly designated 
isolated rural areas are only required to determine conformity for 
the first time when a non-exempt federal highway or transit project 
requires funding or approval after the end of the one-year grace 
period.
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    Metropolitan areas that are designated nonattainment for the 8-hour 
ozone and PM2.5 standards can make transportation plan and 
TIP conformity determinations during their respective grace periods on 
a voluntary basis. In order to avoid a lapse, DOT must make its 
conformity determination prior to the end of the grace period. The 
timing of the next required plan and TIP conformity determinations will 
be determined pursuant to the frequency requirements in Sec.  93.104 of 
the conformity rule, starting from the date of DOT's first conformity 
determination that includes a new regional emissions analysis under the 
new standards, even if this occurs prior to the end of the grace 
period. Thus, conformity determinations will always be conducted at 
intervals as required by the regulations.
    Similarly, a conformity determination for a non-exempt FHWA/FTA 
project in a metropolitan, donut, or isolated rural area could be 
prepared during the one-year grace period, and submitted to DOT. DOT 
can make its conformity determination for such a project during the 
grace period. However, a conformity determination for a new standard 
might not be necessary if FHWA and FTA take all necessary approval 
actions prior to the end of the grace period. Once the conformity grace 
period expires, a project-level conformity determination is required 
whenever non-exempt projects complete the NEPA process, as defined in 
40 CFR 93.101. For projects that complete the NEPA process prior to the 
end of the conformity grace period without a conformity determination 
for a new standard, a project-level conformity determination would be 
required for the next project phase that requires FHWA/FTA approval.
2. Regional Emissions Analysis Requirements in 8-hour Ozone and 
PM2.5 Areas
    One commenter requested clarification on whether different regional 
emissions analysis requirements will apply under the 1-hour and 8-hour 
ozone standards. In this rulemaking, EPA did not change the regional 
emissions analysis requirements in Sec.  93.122 for existing and new 
nonattainment and maintenance areas. Therefore, new 8-hour ozone and 
PM2.5 areas must adhere to the same emissions analysis requirements as 
existing areas. For example, only 8-hour ozone nonattainment areas 
classified as serious, severe and extreme whose metropolitan planning 
area contains an urbanized population over 200,000 are required to meet 
the more rigorous transportation modeling requirements contained in 
Sec.  93.122(b) of the conformity rule. Based on EPA's April 15, 2004 
designations and classifications for 8-hour nonattainment areas as 
published in the Federal Register on April 30, 2004 (69 FR 23858), all 
nonattainment areas classified as serious or severe under the 8-hour 
ozone standard are already meeting these modeling requirements because 
they had a similar or higher classification under the 1-hour ozone 
standard. There are no nonattainment areas classified as extreme under 
the 8-hour standard.
    However, even if these areas were required to expand the geographic 
area covered by their transportation model, these expanded areas would 
have a two-year grace period to revise their model to cover the full 8-
hour ozone nonattainment area, as described in Section XXIII. and Sec.  
93.122(c) of today's action. Similarly, if there are 8-hour ozone 
nonattainment areas initially classified as serious or severe with an 
urbanized population greater than 200,000 that were never previously 
required to comply with the modeling requirements contained in Sec.  
93.122(b), either because their 1-hour classification was lower or 
their urbanized population was under 200,000, these areas would also 
have a two-year grace period to develop a new transportation model that 
satisfies these requirements. During the two-year grace period, 
affected areas must meet the requirements of Sec.  93.122(d) of the 
conformity rule.
    In addition, PM2.5 nonattainment areas and all other 8-
hour ozone nonattainment areas are also required to

[[Page 40013]]

comply with the transportation modeling requirements contained in Sec.  
93.122(d). This section requires these areas to continue to model 
regional emissions using all of the procedures described in Sec.  
93.122(b) where it has been their past practice. In other words, if an 
area has previously been required to demonstrate conformity and the 
area's transportation model and modeling practices either fully or 
partially complied with the requirements of Sec.  93.122(b), the area 
must continue to model regional emissions for the 8-hour ozone and/or 
PM2.5 standard using procedures which continue to meet these 
same aspects of the Sec.  93.122(b) requirements that were previously 
met. Otherwise, areas may estimate regional emissions using any 
appropriate methods that account for growth in vehicle miles traveled 
(VMT) and consider future economic activity, transit alternatives and 
transportation system policies, as determined through the interagency 
consultation process.
3. Timely Implementation of TCMs in Approved SIPs
    Section 93.113 of the existing conformity rule requires that 
transportation plans, TIPs, and projects which are not from a 
conforming plan and TIP must provide for the timely implementation of 
TCMs from an approved SIP. EPA notes that today's final rule does not 
change the implementation of these requirements for any existing or new 
nonattainment or maintenance area, including 8-hour nonattainment areas 
that have approved 1-hour SIPs that contain TCMs.
    Clean Air Act section 176(c) requires that TCMs in approved SIPs be 
implemented in a timely manner according to the schedules in the SIP. 
This requirement is not contingent on what type of SIP, pollutant, or 
standard for which the approved TCM was established. Conformity 
determinations for any pollutant and standard must provide for the 
timely implementation of TCMs in approved SIPs, including TCMs in 
approved SIPs for the 1-hour ozone standard after that standard is 
revoked. Such TCMs can only be removed from the 1-hour SIP through the 
SIP process.
4. Multi-State Nonattainment Areas and Nonattainment Areas With Sub-
Area Budgets
    Some commenters requested clarification regarding how conformity 
would be implemented under the new standards in nonattainment areas 
with multiple MPOs or that cover multiple states. EPA believes that 
today's action is consistent with its existing conformity rule and 
historical precedent that provides flexibility to such areas. For 
example, nonattainment areas with multiple MPOs can establish sub-area 
motor vehicle emissions budgets in their 8-hour ozone or 
PM2.5 SIPs to allow MPOs to do conformity separately, 
provided that all MPOs in such a nonattainment area continue to have 
conforming transportation plans and TIPs. EPA will post implementation 
guidance on its transportation conformity Web site for conformity 
determinations in multi-state and multi-MPO nonattainment areas. Please 
see Section I.B.2. of this notice for information regarding EPA's 
conformity Web site.
5. Donut Areas
    A few commenters requested clarifications pertaining to conformity 
implementation in portions of a nonattainment area that are not 
contained within the area's MPO boundary (i.e., ``donut areas''). 
Specifically, one commenter requested that adjacent MPO and donut areas 
in the same nonattainment area be allowed to submit individual 
conformity determinations.
    In general, EPA believes that regional emissions for an entire 
nonattainment area, including any donut portion, must be considered at 
the time a conformity determination is made to ensure that all 
transportation activities in that area conform. Therefore, EPA has not 
changed the current rule's requirements and existing precedent for 
donut areas in response to this comment. Areas that contain a donut 
portion should refer to the November 5, 2003 proposal (68 FR 62695-
62696) for more information on the requirements for demonstrating 
conformity in donut areas.
    Another commenter requested that EPA designate state transportation 
and air quality agencies as the lead agencies for conducting and 
completing conformity determinations for donut areas. This commenter 
believed that this process for demonstrating conformity in donut areas 
needs to be formalized through the interagency consultation process 
and/or a memorandum of understanding.
    EPA anticipates that the state departments of transportation may 
take the lead in conducting regional emissions analyses for the donut 
portion in some nonattainment areas. However, there may be cases where 
an adjacent MPO is better suited to conduct such analyses or wants to 
include the donut area's projects in its plan and TIP and supporting 
regional emissions analysis. Section 93.105(c)(3) of the conformity 
rule relies on the interagency consultation process (including the MPO 
and state transportation agency) to determine how best to consider 
projects that are planned for donut areas located outside the 
metropolitan area and within the nonattainment or maintenance area in 
the conformity process. Section 93.105 also requires that such 
procedures for demonstrating conformity of donut area projects be 
included in an area's conformity SIP that is approved by EPA. 
Therefore, EPA believes that the existing rule's requirements and the 
flexibility provided by this provision remain appropriate and do not 
need to be revised to address this comment.
    Another commenter raised concerns that in some nonattainment areas 
only portions of the donut area may be included in the MPO's 
transportation model. This commenter also suggested that emissions 
information for such outlying donut portions may not be readily 
available.
    EPA understands that the donut portion of some new nonattainment 
areas may not be included in the adjacent MPO's transportation model 
and may not have as up-to-date or detailed planning information as the 
MPO. The conformity rule provides flexibility for modeling requirements 
in these areas. In fact, existing methods that are used in donut areas 
may already be suitable for conformity determinations. EPA does not 
believe that a travel demand model is required to estimate emissions 
for donut areas in most cases (provided that Sec.  93.122(b) does not 
apply to the nonattainment area). See C.2. of this section for more 
information about the general transportation modeling requirements in 
8-hour and PM2.5 nonattainment areas.
    In addition, the conformity rule requires the use of the latest 
planning assumptions and emissions models that are available at the 
time a conformity analysis begins (Sec. Sec.  93.110 and 93.111). 
Today's change to the latest planning assumptions requirements is 
discussed in Section XX. of this preamble. For most donut areas, the 
most recently available Highway Performance Monitoring System (HPMS) 
estimates of VMT may be the only source of travel data available, and 
thus, should be used. Some donut areas may also need to rely on 
national default data (e.g., speeds and vehicle registration data) 
included in EPA's most recent emissions model, MOBILE6.2, when 
estimating emissions if no local data is available for the donut area 
and it appears that the default data is more representative than the 
local information for the adjacent metropolitan area. In such a case 
the conformity determination for the area

[[Page 40014]]

should contain an explanation of why the default data was used for a 
portion of the nonattainment area. The interagency consultation process 
must be used to determine which planning assumptions are considered the 
latest and best for demonstrating conformity for donut areas prior to 
the expiration of the one-year conformity grace period.
6. Isolated Rural Areas
    We received one comment that supported our November 5, 2003 
proposal for implementing the conformity grace period in isolated rural 
areas. This commenter believed that due to the rarity of new non-exempt 
projects in these areas, requiring a conformity determination for only 
exempt projects would be a misuse of resources. EPA agrees with this 
comment, and therefore, clarified in the November 2003 proposal and 
today's final rule that conformity in isolated rural areas is required 
only when a non-exempt FHWA/FTA project(s) needs funding or approval. 
See A. of this section and the November 2003 proposal (68 FR 62696) for 
more information.

D. When and For What Ozone Standard Does Conformity Apply in Areas With 
an Early Action Compact for the 8-hour Ozone Standard?

1. Description of Final Rule
    EPA has provisionally deferred into the future the effective date 
of 8-hour ozone nonattainment designations for areas participating in 
an Early Action Compact (EAC). The deferral of the 8-hour designation 
effective date is contingent upon the participating area's adherence to 
all the terms and milestones of its EAC, as described in EPA's November 
14, 2002 memorandum entitled, ``Schedule for 8-Hour Ozone Designations 
and its Effect on Early Action Compacts,'' the December 16, 2003 
proposed EAC rule (68 FR 70108), and the April 30, 2004 final 
designations rule (69 FR 23864).
    Consistent with Sec.  93.102(d) and Clean Air Act section 
176(c)(6), conformity for the 8-hour ozone standard will not apply 
until one year after the effective date of an EAC area's 8-hour 
nonattainment designation. Therefore, conformity for the 8-hour ozone 
standard will apply in an EAC area only if the area fails to meet all 
the terms and milestones of its compact and the nonattainment 
designation becomes effective. In this case, conformity for the 8-hour 
standard will be required one year after the effective date of EPA's 
nonattainment designation that will occur shortly after a missed EAC 
milestone. Conversely, if the area meets all of the EAC milestones and 
attains the 8-hour ozone standard by December 2007, conformity for the 
8-hour ozone standard would never apply since the area's ultimate 
effective designation would be attainment for the 8-hour ozone 
standard.
    Conformity for the 1-hour ozone standard will continue to apply in 
EAC areas that are currently 1-hour ozone maintenance areas and are 
required to demonstrate conformity for that standard. If a maintenance 
area meets all of its EAC milestones and attains the 8-hour ozone 
standard by December 2007, conformity for the 1-hour standard will no 
longer apply once EPA revokes that standard one year after the 
effective date of EPA's 8-hour attainment designation (i.e., spring 
2009).
    If, however, a 1-hour ozone maintenance area fails to meet a 
milestone in its EAC, EPA would lift its deferral, and the area's 8-
hour ozone nonattainment designation would become effective shortly 
after the missed milestone. Under this scenario, conformity for the 1-
hour ozone standard will continue to apply until one year after the 
effective date of EPA's nonattainment designation. Also occurring at 
one year after the nonattainment designation will be revocation of the 
1-hour ozone standard, expiration of the one-year conformity grace 
period, and the application of conformity for the 8-hour ozone standard 
under Clean Air Act section 176(c)(6).
2. Rationale and Response to Comments
    All commenters who addressed this topic supported EPA's approach 
for deferring the 8-hour ozone conformity requirements in EAC areas 
through deferral of the effective date of 8-hour designations. One of 
these commenters believed that EPA's proposal can yield positive 
results while imposing minimal constraints on states and localities. 
Other commenters believed that the EAC policy is a proactive approach 
for meeting Clean Air Act requirements and should reduce emissions and 
provide for attainment without the need of the conformity requirements. 
EPA agrees with these comments.
    Another commenter raised concerns regarding how conformity would be 
implemented in 8-hour ozone nonattainment areas that are covered only 
partially by an EAC. For example, in a nonattainment area that contains 
a few donut counties that are not covered by a metropolitan area's EAC, 
this commenter argued that the conformity status of such an EAC would 
not lapse if the donut counties could not demonstrate conformity by the 
expiration of the one-year grace period. However, since 8-hour ozone 
nonattainment areas were not designated as the commenter described, EPA 
is not providing guidance in today's notice for such a situation.

IV. General Changes in Interim Emissions Tests

A. Background

    Conformity determinations for transportation plans and TIPs as well 
as transportation projects not from a conforming plan and TIP must 
include a regional emissions analysis that fulfills certain Clean Air 
Act provisions. Section 176(c) requires that transportation activities 
in all nonattainment and maintenance areas must not worsen air quality. 
In addition, transportation activities in ozone and CO nonattainment 
areas of higher classifications also need to contribute emission 
reductions towards attainment.
    The conformity rule provides for several different regional 
emissions analysis tests that satisfy these Clean Air Act requirements 
in different situations. Once a SIP with a motor vehicle emissions 
budget (``budget'') is submitted for an air quality standard and EPA 
finds the budget adequate or approves it as part of the SIP, conformity 
is demonstrated using the budget test for that pollutant or precursor, 
as described in Sec.  93.118 of the conformity rule. Before an adequate 
or approved SIP budget is available, conformity of the transportation 
plan, TIP, or project not from a conforming plan and TIP is generally 
demonstrated with the interim emissions tests, as described in Sec.  
93.119.
    The following subsections describe the final changes to the interim 
emissions tests (under Sec.  93.119). Sections V., VI., and VII. 
describe the application of these tests in different 8-hour ozone and 
PM2.5 areas (under Sec.  93.109).

B. Baseline Year Test for 8-Hour Ozone and PM2.5 Areas

1. Description of Final Rule
    We are adding the following tests to the conformity rule for 8-hour 
ozone and PM2.5 nonattainment areas:
     The ``less-than-2002 emissions'' test, and
     the ``no-greater-than-2002 emissions'' test.

Under these interim emissions tests, conformity would be demonstrated 
if the emissions from the proposed transportation system are either 
less than or no greater than 2002 motor

[[Page 40015]]

vehicle emissions in a given area. Regulatory text for the 2002 
baseline year tests can be found in Sec.  93.119. See Sections V.-VII. 
for how these tests will be applied in various 8-hour ozone and 
PM2.5 areas.
    EPA is not changing the 1990 baseline year tests for 1-hour ozone, 
CO, PM10 and NO2 areas that do not have adequate 
or approved SIP budgets. However, Sec.  93.119 has been reorganized to 
include the provisions for new 8-hour ozone and PM2.5 areas.
    Consistent with current practice, the interagency consultation 
process under Sec.  93.105(c)(1)(i) must be used to determine the 
latest assumptions and models for generating 2002 motor vehicle 
emissions to complete either baseline year test. All 8-hour and 
PM2.5 areas will be submitting baseline SIP inventories for 
the year 2002. As described in the proposal, the 2002 baseline year 
test can be completed with the SIP's 2002 motor vehicle emissions 
inventory, if the SIP has been submitted in time for the current 
conformity determination. Draft 2002 baseline year emissions from a SIP 
inventory under development or the consultation process could also be 
used to develop 2002 baseline year emissions as part of the conformity 
analysis. EPA believes that a submitted or draft 2002 SIP inventory may 
be the most appropriate source for completing the 2002 baseline year 
tests for an area's first conformity determination under the new 
standards. This is due to the fact that the 2002 SIP inventories should 
be under development at the same time as these determinations, and such 
inventories should be based on the latest available data at the time 
they are developed. Whatever the source, the 2002 baseline year 
emissions level that is used in conformity must be based on the latest 
planning assumptions available for the year 2002, the latest emissions 
model, and appropriate methods for estimating travel and speeds as 
required by Sec. Sec.  93.110, 93.111 and 93.122 of the conformity 
rule.
2. Rationale and Response to Comments
    Most commenters supported the proposal to use 2002 for the baseline 
year tests for the new air quality standards. These commenters also 
supported the use of the interagency consultation process to determine 
how the 2002 baseline emission level is calculated. However, a few 
commenters supported using a more recent baseline year (i.e., 2003, 
2004, 2005) for conformity analyses completed before 8-hour ozone or 
PM2.5 SIP budgets are found adequate. These commenters 
argued that a more recent year should be used when reliable data are 
available to ensure that additional project approvals are not made 
during interim years with an artificially high 2002 motor vehicle 
emissions inventory.
    EPA continues to believe that the year 2002 is more appropriate 
than either the 1990 baseline year or a more recent baseline year, as 
some commenters suggested. EPA believes that it is important to have 
transportation and air quality planning time frames coordinated. Having 
consistent baseline years for SIPs, conformity determinations and other 
emission inventory requirements helps to achieve this goal. This was 
the rationale for maintaining 1990 as the baseline year for conformity 
tests in existing areas, and past experience indicates that having 
similar baseline years for SIP and conformity planning purposes has 
worked well.
    As described in the November 2003 proposal, EPA has selected 2002 
as the baseline year for SIP inventories under the new 8-hour ozone and 
PM2.5 standards. EPA's November 18, 2002 memorandum, ``2002 
Base Year Emission Inventory SIP Planning: 8-hr Ozone, 
PM2.5, and Regional Haze Programs,'' identifies 2002 as the 
emission inventory base year for the SIP planning process to address 
both of these pollutants and standards. EPA's April 30, 2004 final 8-
hour ozone implementation rule also establishes 2002 as the base year 
for 8-hour ozone SIP inventories (69 FR 23951), as described in the 
June 2, 2003 proposal (68 FR 32810). Finally, EPA's Consolidated 
Emissions Reporting Rule (CERR) requires submission of emission 
inventories every three years, and 2002 is one of the required years 
for such updates. EPA continues to believe that coordinating 
conformity's baseline with other data collection and inventory 
requirements would allow state and local governments to use their 
resources more efficiently. In addition, since conformity is to be 
measured against a SIP it is appropriate to use the baseline year that 
will be used for SIP planning.
    Furthermore, a 2002 baseline year is an appropriate measure for 
meeting Clean Air Act conformity requirements to not worsen air quality 
prior to adequate SIP budgets being established. EPA notes that 
emission inventories are generally not submitted until approximately 
two years after the year for which they are calculated. The 2002 
inventories are scheduled to be submitted by the states to EPA in June 
of 2004, the year designations are made for the 8-hour ozone and 
PM2.5 standards. In addition, emission inventories are not 
expected to vary by much in the few years following 2002. Emission 
inventories are generally trending downward, but year to year changes 
are generally small. Any advantage gained by using the most recent 
available inventory as the baseline for conformity purposes would be 
offset by the loss of coordination with other agencies and processes 
that will be possible by the use of 2002 as the baseline year. 
Therefore, EPA is retaining in this final rule the 2002 baseline year 
tests for conformity under the new air quality standards.
    Finally, EPA is responding today to a comment that was raised in 
the context of the June 2, 2003 proposed 8-hour ozone implementation 
rule. A commenter supported using only the motor vehicle emissions 
inventories for the year 2002 as de facto interim motor vehicle 
emissions budgets for conformity determinations, during the time period 
before 8-hour areas have adequate or approved SIP budgets for the 8-
hour standard. This commenter also suggested that the motor vehicle 
emissions inventory could be decreased 3% per year between the base 
year of 2002 and the attainment year, to represent ``reasonable further 
progress'' for the transportation sector.
    EPA understands the commenter's point that the 2002 inventory is 
similar to a budget, in that both a 2002 baseline inventory and a SIP 
budget that is established to meet a Clean Air Act requirement serve as 
an emissions ceiling on future transportation actions. However, EPA 
does not agree that the 2002 baseline inventory could be used as a ``de 
facto budget'' and replace the interim emissions test requirements in 
today's final rule.
    As described below, prior to adequate or approved SIP budgets being 
established, 8-hour ozone areas that are classified as moderate or 
higher are generally required to complete both the build-less-than-no-
build and less-than-2002 interim emissions tests. Areas that are 
marginal or designated nonattainment under subpart 1 of part D of title 
1 of the Clean Air Act (``subpart 1 areas'') could, in general, choose 
to use either the no-greater-than-2002 or the build-no-greater-than-no-
build test prior to an 8-hour SIP. Finally, all 8-hour ozone areas have 
the option to submit a reasonable further progress SIP with budgets 
early and use the budget test, instead of the interim emissions 
test(s).
    EPA appreciates the commenter's idea to decrease inventories 
incrementally for the purpose of the baseline year conformity test. 
However, given that EPA did not propose and receive public comment on 
this idea, the commenter's

[[Page 40016]]

suggestion is not included in today's final rule. Furthermore, EPA 
believes that the option for an area to submit an early 8-hour SIP that 
meets Clean Air Act requirements provides sufficient flexibility to 
transition areas quickly to the budget test for future conformity 
determinations, when desired. Please see Sections V. and VI. of the 
preamble for more information regarding the regional emissions tests 
that apply for 8-hour conformity determinations.

C. Build/No-Build Test for Certain Existing and New Nonattainment Areas

1. Description of Final Rule
    EPA is revising the build/no-build test for certain existing and 
new nonattainment areas. Specifically, the final rule amends Sec.  
93.119 to create the ``build-no-greater-than-no-build'' test, where 
conformity is demonstrated if emissions from the proposed 
transportation system (``build'' or ``action'' scenario) are less than 
or equal to emissions from the existing transportation system (``no-
build'' or ``baseline'' scenario).
    Under today's final rule, the build-no-greater-than-no-build test 
is available to the following subset of new and existing areas:
     8-hour ozone areas of marginal classification,
     8-hour ozone areas designated nonattainment under subpart 
1 of part D of title 1 of the Clean Air Act (``subpart 1 areas''),
     All PM2.5 areas,
     1-hour ozone areas of marginal and below classifications 
(i.e., Section 185A, incomplete data, and sub-marginal areas),
     CO areas of moderate classification with design values 
less than 12.7 ppm,
     Not classified CO areas,
     All PM10 areas, and
     All NO2 areas.

    Sections V., VI., and VII. of this rule provide more detail 
regarding the application of the build/no-build test in various 8-hour 
ozone and PM2.5 areas.
    For areas that would be using the build-no-greater-than-no-build 
test, EPA is also modifying the existing rule so that a regional 
emissions analysis would not be necessary for analysis years where the 
build and no-build scenarios contain exactly the same transportation 
projects and are based on exactly the same planning assumptions, for 
the reasons described below. Such a case may occur in smaller areas 
that do not have projects planned for earlier years in the regional 
emissions analysis, and population, land use, economic, and other 
assumptions do not change between the build and no-build scenarios for 
those years. Under the final rule, a regional emissions analysis would 
continue to be required for any applicable years where the action and 
baseline scenarios contain different projects and are based on 
different assumptions.
    This change can be found in Sec.  93.119(g)(2) of the final rule 
regulatory text. The rule requires that the conformity determination 
include documentation that a regional emissions analysis is not 
completed for analysis years in which no new projects are proposed and 
no change in planning assumptions has occurred.
    Finally, Sec.  93.119 has been reorganized in general to 
accommodate the above and other changes articulated in this final rule 
for new and existing areas.
2. Rationale and Response to Comments
    As explained in the November 5, 2003 proposal, EPA believes that 
allowing certain areas to use a build-no-greater-than-no-build test is 
consistent with Clean Air Act section 176(c)(3)(A)(iii), which 
specifically requires that transportation plans and TIPs contribute to 
annual emissions reductions only in the higher classifications of ozone 
and CO areas. This statutory provision does not apply to other types of 
nonattainment areas that are required to demonstrate only that 
transportation activities do not cause or contribute to new violations, 
increase the frequency or severity of existing violations, or delay 
timely attainment, pursuant to Clean Air Act section 176(c)(1)(B). EPA 
believes that if the ``build'' scenario emissions are no greater than 
(i.e., less than or equal to) the ``no-build'' scenario emissions, that 
such a demonstration is made, since only an increase in emissions would 
worsen air quality.
    This change to the build/no-build test also makes its 
implementation consistent with the implementation of the baseline year 
tests: In ozone and CO areas of higher classifications, expected 
emissions from the proposed transportation system must be less than 
emissions in the baseline year, while in all other areas, expected 
emissions must be no greater than emissions in the baseline year. For 
further discussion of the rationale for how and where the baseline year 
tests apply, please refer to the preamble to the January 11, 1993 
proposed rule (58 FR 3782-3784), the preamble to the July 9, 1996 
proposed rule (61 FR 36116-36117), and the November 5, 2003 proposal 
(68 FR 62701, 62705).
    Most commenters supported EPA's proposal to provide the build-no-
greater-than-no-build test in certain nonattainment areas. Many of 
these commenters agreed with EPA's interpretation of the Clean Air Act 
section 176(c)(3)(A)(iii) that ozone nonattainment areas that are not 
classified moderate or above, lower classified CO nonattainment areas 
and all PM10, NO2 and PM2.5 areas are 
not required to demonstrate annual emissions reductions for conformity 
purposes. One commenter stated that, from a practical standpoint, the 
build and no-build options are often identical and believed that there 
is no reason to require emissions reductions prior to the submission of 
a SIP for such areas. A few commenters also believed that this rule 
revision would provide flexibility and resolve previous conformity 
issues in areas with few transportation projects, only non-regionally 
significant projects, or projects planned for only certain years of the 
transportation plan. EPA agrees with these comments.
    A few commenters also believed that the proposed build-no-greater-
than-no-build test should be available to all 8-hour ozone 
nonattainment areas, not just marginal or subpart 1 areas. Two of these 
commenters believed that EPA should extend this flexibility as 
satisfying the Clean Air Act section 176(c)(1)(B) requirement, that 
transportation plans only be required to not make air quality worse. 
However, EPA believes that extending this approach to CO and ozone 
areas of higher classifications would violate Clean Air Act section 
176(c)(3)(A)(iii), which also requires transportation plans and TIPs in 
these areas to contribute to annual emissions reductions. The build-no-
greater-than-no-build test does not satisfy this requirement.
    In contrast, two commenters did not agree with EPA's proposal to 
change the previous build-less-than-no-build test to a build-no-
greater-than-no-build test in certain nonattainment areas. One of these 
commenters was concerned that changing the build/no-build test in 
certain areas may hinder future ozone reductions by not requiring the 
implementation of transportation activities that would reduce 
emissions. This same commenter, however, agreed that this proposed 
revision to the build/no-build test would simplify the planning 
process. Another commenter did not agree with EPA's proposal because 
this commenter believed that the conformity requirements should be the 
same for all parties regardless of size or classification. The 
commenter believed that all nonattainment and maintenance areas should 
contribute to reducing emissions not only to improve their own air 
quality but also to benefit

[[Page 40017]]

the air quality in nearby airsheds as well. Further, the commenter 
argued that EPA's proposal could rectify a previous issue with the 
build/no-build test where the first analysis year is sufficiently close 
to the present year (the year in which the regional emissions analysis 
is being conducted) such that all of the non-exempt projects in the 
action scenario are also in the baseline scenario.
    EPA believes that the Clean Air Act makes the distinction in 
requirements between areas of different pollutants and classifications 
and thus certain areas are not required to contribute reductions 
towards attainment prior to SIP submission. Therefore, EPA is not 
changing the final rule in response to these comments.
    Another commenter requested clarification on the level of precision 
that is required to demonstrate conformity using the proposed build-no-
greater-than-no-build test. For example, if an analysis resulted in 
emissions from the baseline (no-build) scenario being 9,000 pounds/day 
(4.500 tons/day) and emissions from the action (build) scenario being 
10,998 pounds/day (5.499 tons/day), the commenter asked whether the 
agency performing the analysis could round both values off to 5 tons/
day and claim that the build-no-greater-than-no-build test had been 
satisfied. This commenter believed that leaving this issue to be 
resolved through interagency consultation does not recognize that there 
are separate conformity interagency consultation rules for each region 
or perhaps each state or metropolitan area. The commenter questioned 
whether consistency in implementing the build-no-greater-than-no-build 
test could be maintained without sufficient guidance.
    EPA believes that, at a minimum, rounding conventions used in 
conformity should be consistent with the level of precision used for 
the motor vehicle emissions budget in the local SIP. Rounding 
conventions should be discussed through the interagency consultation 
process and consider past conformity practices for the area. EPA notes 
that today's final rule only addresses how conformity analyses are 
performed; budgets cannot be rounded or changed from the emissions 
level that is determined by the SIP. If questions remain or if the area 
has never developed a local SIP, the interagency consultation process 
is the correct place to deal with questions of precision and rounding. 
The precision used in the development of local emissions inventories 
may vary depending on the size of the area and the resources available 
for the analysis. Decisions on rounding conventions for conformity 
analyses need to be consistent with local analysis methods and cannot 
easily be made at the national level. However, even given local 
variations in analysis methods, it is clear in the commenter's example 
that the build scenario produces emissions greater than the no-build 
scenario, and thus the test is not passed.
    EPA also notes that the final rule will also reduce the resource 
burden for analysis years where no new projects are proposed to be 
completed and assumptions do not change. Under the previous rule, a 
regional emissions analysis is required for all analysis years, even if 
no new projects are proposed for analysis years in the distant future. 
For such analysis years, the emissions from the build and no-build 
scenarios contain the same projects and assumptions, and therefore, 
result in exactly the same level of emissions.
    EPA believes that in such cases it is obvious that the build-no-
greater-than-no-build test is passed without calculating the emissions 
for such analysis years. Furthermore, the Clean Air Act requirements to 
not worsen air quality or delay timely attainment may be met by 
documenting in the conformity determination that projects, assumptions, 
and thus emissions would remain the same for affected analysis years.
    Most commenters supported EPA's proposal to not require a regional 
analysis in years where the build and no-build scenarios are exactly 
the same with the same projects and planning assumptions. Many of these 
commenters believed that the proposal would reduce burden on small 
urban areas with relatively few projects and resources for conducting 
conformity analyses. One commenter also believed that this proposal 
would prevent conformity lapses and would allow states to focus on 
those nonattainment areas with more transportation projects and more 
severe air quality issues. Two commenters believed this flexibility 
should also be extended to ozone nonattainment areas of higher 
classifications.
    EPA agrees that this approach will likely relieve some of the 
burden of the conformity process on small areas with few projects and 
less serious air quality problems. However, ozone areas with higher 
classifications are required to meet a build-less-than-no-build test so 
this provision of today's final rule does not apply. In these areas, 
transportation plans and TIPs actually have to reduce emissions from 
current levels.
    One commenter raised concerns with our proposal to waive regional 
analysis requirements for future analysis years when the build and no-
build scenarios are exactly the same. This commenter did not agree with 
EPA's logic for the proposed rule revision, stating that the build and 
the no-build cases will always contain different assumptions regarding 
growth. Another commenter pointed out that EPA's proposal would be 
beneficial only when new projects are programmed in the later years of 
a plan, and no new projects are planned for the early years of the plan 
or TIP. However, in the reverse situation when projects are added in 
the early years of the TIP or plan but not in the later years, the 
commenter indicated that the effect of those projects would need to be 
reflected in the build scenario throughout the horizon years of the 
plan, via different VMT and speed estimates. In this case, the 
commenter stated that all analysis years should be modeled and included 
in the conformity determination.
    EPA agrees with the commenter's understanding that the logic given 
in the November 5, 2003 proposal for this change was incorrect. We 
agree that an area would have different projects and assumptions in 
later years where projects were added in earlier years (these projects 
would always and only be in the build case for any years). However, we 
still think there are limited cases where projects and assumptions for 
both scenarios could be the same such as in earlier years. EPA believes 
that if the build and no-build scenarios are exactly the same and are 
based on exactly the same planning assumptions, by definition they 
cannot contain different assumptions about growth. This provision is 
intended to only apply in situations when the build and no-build 
scenarios are exactly the same. If there are any differences in the 
build and no-build scenarios, including differences in planning 
assumptions, speed or VMT, this provision would not apply.
    One commenter believed that this flexibility should be available 
through the interagency consultation process, and that EPA should 
modify the conformity regulation to allow it subject to agreement among 
affected parties though the interagency consultation process. EPA 
agrees that consultation should be used to determine when this 
flexibility applies, but no rule change is needed to do that.
    Finally, several commenters raised general concerns about the 
build/no-build test and offered other suggested changes to the test to 
address these concerns. For example, a few commenters did not believe 
that the ``no-build'' scenario always provides an

[[Page 40018]]

appropriate basis for conformity demonstrations, particularly in the 
outyears of the transportation plan. To address this issue, one 
commenter proposed that for all analysis years in the second 10 years 
of the transportation plan, the ``no-build'' scenario should be the 
``build'' scenario from the previous analysis year.
    EPA agrees that there are limitations in the usefulness of the 
build/no-build test for assessing longer-term air quality impacts of 
highway and transit projects. In fact, this is the primary reason that 
the build/no-build test is an interim test prior to the availability of 
an adequate or approved SIP budget. EPA does not believe the suggested 
changes to the build/no-build test are necessary and would ensure 
protection of air quality during this interim period. For example, the 
suggested change proposed by one of the commenters could allow 
emissions increases. In addition, many commenters supported the 
flexibility to choose between build/no-build and baseline year tests, 
as described in Sections V., VI., and VII. Since these general comments 
were not germane to the proposal, we have included a full response to 
these comments in the separate response to comments document, which is 
in Public Docket I.D. no. OAR-2003-0049.

D. Test Requirements for Ozone and CO Nonattainment Areas of Higher 
Classifications

1. Description of Final Rule
    EPA is retaining the requirement that ozone and CO areas of higher 
nonattainment classifications must meet both the build-less-than-no-
build and less-than-baseline year tests to demonstrate conformity in 
the period before SIP budgets are available. This provision will affect 
moderate and above 1-hour and 8-hour ozone areas, moderate CO areas 
with design values greater than 12.7 ppm, and serious CO areas. This 
requirement is identical to the requirement of the existing conformity 
rule for these areas, and was the first of three options proposed for 
regional emissions analyses before adequate or approved SIP budgets are 
established.
    EPA had requested comment on the following proposed options for 
these areas:
    (1) Complete both the build-less-than-no-build and less-than-
baseline year tests;
    (2) Complete either the build-less-than-no-build or less-than-
baseline year test; or
    (3) Require that only one of these tests be met and eliminate the 
second test as an option altogether.
    The first option, which EPA has selected for the final rule, will 
retain the current conformity rule requirement that such areas use both 
the current build-less-than-no-build test and the less-than-baseline 
year test. Under this option, emissions from the proposed 
transportation system (build) will have to be less than emissions from 
the existing system (no build) and less than emissions in 1990 (for 
higher classification 1-hour ozone and CO areas) or 2002 (for higher 
classification 8-hour ozone areas). See the proposal for further 
background information on options 2 and 3 (November 5, 2003, 68 FR 
62699-62700).
2. Rationale and Response To Comment
    Based on our review of the proposal, the existing requirements of 
the conformity rule, and comments submitted, EPA has concluded that 
option 1, the existing conformity requirements, will better meet the 
dual statutory requirements for ozone and CO areas of higher 
classifications. These areas must demonstrate that transportation 
activities not cause or contribute to violations of the standards or 
delay timely attainment of a standard (Clean Air Act section 
176(c)(1)(B)) and that such activities also contribute to annual 
emissions reductions (Clean Air Act section 176(c)(3)(A)(iii)).
    EPA's proposal was intended to explore potential alternatives in an 
effort to provide the most flexible and least burdensome way of meeting 
statutory requirements. When EPA first promulgated the transportation 
conformity rule (January 11, 1993, 58 FR 3782), EPA determined that 
moderate and above 1-hour ozone areas and CO areas of higher 
classifications would have to meet both the build-less-than-no-build 
test and the less-than-baseline year test to satisfy both applicable 
statutory requirements that transportation activities not cause or 
contribute to violations of the standards (Clean Air Act section 
176(c)(1)(B)) and that such activities contribute to annual emissions 
reductions (Clean Air Act section 176(c)(3)(A)(iii)). EPA also 
discussed our rationale for these areas in a July 9, 1996, proposed 
rule (61 FR 36116-36117).
    Although the majority of the comments supported option 2, a choice 
between either the build/no-build or baseline year test, these 
commenters primarily supported this option out of a stated desire to 
obtain greater flexibility in meeting conformity requirements. No 
commenters provided any further rationale for the option or explained 
how the statutory requirements could be satisfied with only one test. 
In contrast, the commenters supporting option 1, continuation of the 
existing rule requirement to meet both the tests, provided compelling 
arguments indicating that both tests would be necessary to meet the 
statutory requirements. Further, comments on option 3 noting why either 
test would be superior provided additional indication that either test 
by itself could not meet both statutory obligations. In the face of 
these comments, as explained below EPA does not believe it can alter 
the current rule requiring the use of both tests.
    The totality of the comments led EPA to conclude that if only the 
baseline test were required, in an area where motor vehicle emissions 
were declining significantly as a result of technology improvements in 
vehicle engines and fuels, the transportation plan itself might not be 
contributing to emissions reductions while the area as a whole was 
still meeting the baseline test. This would not meet the statutory 
requirement that such transportation activities themselves must 
contribute to emissions reductions. In contrast, in ozone and CO areas 
of higher classifications, the build/no-build test alone would not 
guarantee that emissions from the planned transportation system are 
less than emissions in the baseline year, even if emissions from the 
planned transportation system (the build case) are less than the 
current transportation system (the no-build case). This could fail to 
meet the statutory requirement that activities not contribute to 
violations of the standard.
    Thus, based on the Agency's reasoning in past conformity rules and 
the comments submitted in this rulemaking, EPA believes that it must 
continue to require the use of both the baseline year and build/no-
build tests in ozone and CO areas of higher nonattainment 
classifications prior to the availability of SIP budgets in order to 
satisfy applicable statutory obligations. In light of this conclusion, 
EPA is not responding in detail in this preamble to the numerous 
comments indicating policy choices for which of the two tests should be 
chosen or how the choice should be made, since EPA is requiring the use 
of both tests on legal grounds. A full response to all comments is 
included in the separate response to comments document available in the 
docket for this final rule.

[[Page 40019]]

V. Regional Conformity Tests in 8-hour Ozone Areas That Do Not Have 1-
Hour Ozone SIPs

A. Description of Final Rule

    This section covers the provisions EPA is finalizing in today's 
rule for regional emissions analyses in 8-hour ozone areas that do not 
have an existing 1-hour ozone SIP with applicable budgets. These 8-hour 
ozone areas either were never designated nonattainment under the 1-hour 
ozone standard or were 1-hour ozone nonattainment areas that never 
submitted a control strategy SIP or maintenance plan with approved or 
adequate budgets. A regional emissions analysis is the part of a 
conformity determination that assesses whether the emissions produced 
by transportation activities are consistent with state, local, and 
federal air quality goals. EPA describes the final rule in four parts, 
as in the proposal: Conformity when 8-hour budgets are available, 
conformity before 8-hour budgets are available, conformity in clean 
data areas, and general implementation of regional emissions tests.
1. Conformity After 8-Hour Ozone SIP Budgets Are Adequate or Approved
    Once a SIP for the 8-hour ozone standard is submitted with a 
budget(s) that EPA has found adequate or approved, the budget test must 
be used in accordance with Sec.  93.118 to complete all future 
applicable regional emissions analyses for 8-hour conformity 
determinations. In other words, once EPA finds a budget from an 8-hour 
ozone SIP adequate or approves an 8-hour ozone SIP that includes such a 
budget, the interim emissions test(s) will no longer apply for that 
precursor. This provision is found in Sec.  93.109(d)(1) of today's 
rule.
    The first 8-hour ozone SIP could be a control strategy SIP required 
by the Clean Air Act (e.g., rate-of-progress SIP or attainment 
demonstration) or a maintenance plan. However, 8-hour ozone 
nonattainment areas ``are free to establish, through the SIP process, a 
motor vehicle emissions budget [or budgets] that addresses the new 
NAAQS in advance of a complete SIP attainment demonstration. That is, a 
state could submit a motor vehicle emissions budget that does not 
demonstrate attainment but is consistent with projections and 
commitments to control measures and achieves some progress towards 
attainment'' (August 15, 1997, 62 FR 43799). A SIP submitted earlier 
than otherwise required can demonstrate a significant level of 
emissions reductions from the current level of emissions, instead of 
the specific percentage required by the Clean Air Act for moderate and 
above ozone areas. For example, an area could submit an early 8-hour 
ozone SIP that demonstrates a 5-10% reduction of emissions in the year 
2007, from 2002 baseline year emissions. An approvable early 8-hour SIP 
would include emissions inventories for all emissions sources for the 
entire 8-hour nonattainment area and would meet applicable requirements 
for reasonable further progress SIPs. For more information on 
establishing an early SIP and how it could be used for conformity, 
please refer to the final 8-hour ozone implementation rule (April 30, 
2004, 69 FR 23951).
    Air quality agencies responsible for developing 8-hour ozone SIPs 
must consult on their development with the relevant state and local air 
quality and transportation agencies per Sec.  93.105(b). EPA Regions 
are available to assist on an ``as needed'' basis, including 
consultation on the development of early 8-hour ozone SIPs.
2. Conformity Before 8-Hour Ozone SIP Budgets Are Adequate or Approved
    Before adequate or approved 8-hour ozone SIP budgets are 
established in 8-hour ozone areas that do not have 1-hour ozone SIPs, 
the regional emissions analysis is done using one or two interim 
emissions tests, depending on the area's classification or designation 
as described below. These provisions are found in Sec.  93.109(d)(2)-
(4) of today's rule.
    Marginal and below classifications and subpart 1 areas. These 8-
hour ozone nonattainment areas include: 8-hour ozone areas classified 
marginal and 8-hour ozone areas designated nonattainment under Clean 
Air Act subpart 1. These areas must pass one of the following tests in 
accordance with Sec.  93.119 for conformity determinations that occur 
before adequate or approved 8-hour ozone SIP budgets are in place:
     The build-no-greater-than-no-build test, or
     The no-greater-than-2002 emissions test.

That is, emissions in all analysis years from the transportation 
system, as modified by the proposed transportation plan or TIP, must be 
less than or equal to emissions from either:
     The existing transportation system (the ``no-build'' case) 
in each of those analysis years, or
     The transportation system in 2002.

A discussion of the interim emissions tests can be found in Section IV. 
See also EPA's April 30, 2004 final 8-hour ozone implementation rule 
(69 FR 23951) for more information on 8-hour ozone areas designated 
under Clean Air Act subpart 1 (``subpart 1 areas'').
    Moderate and above classifications. These areas include: 8-hour 
ozone nonattainment areas classified as moderate, serious, severe, and 
extreme. These areas must pass both of the following tests in 
accordance with Sec.  93.119 for conformity determinations that occur 
before adequate or approved 8-hour ozone SIP budgets are in place:
     The build-less-than-no-build test, and
     The less-than-2002 emissions test.
    That is, emissions in all analysis years from the transportation 
system, as modified by the proposed transportation plan or TIP, must be 
less than each of the following comparison cases:
     The existing transportation system including projects 
currently under construction (the ``no-build'' case) in each of those 
analysis years, and
     The transportation system in 2002.

For more information regarding these interim emissions tests for 
moderate and above ozone areas, please see Section IV.D.
3. Options for 8-Hour Ozone Areas That Qualify for EPA's Clean Data 
Policy
    In Sec.  93.109(d)(5) of today's rule, EPA is extending the 
conformity rule's flexibility for 1-hour moderate and above ``clean 
data areas'' to 8-hour areas that meet the criteria of the clean data 
policy. As described in the November 5, 2003 proposal, EPA issued a 
policy memorandum on May 10, 1995 that addressed SIP requirements in a 
small number of moderate and above 1-hour ozone areas (entitled 
``Reasonable Further Progress, Attainment Demonstrations, and Related 
Requirements for Ozone Nonattainment Areas Meeting the Ozone National 
Ambient Air Quality Standard''). Please see the November 5, 2003 
proposal for further background on EPA's existing clean data policy and 
conformity options (68 FR 62700-62701).
    Clean data areas under today's final rule are moderate and above 
ozone areas with three years of clean data for the 8-hour ozone 
standard that have not submitted a maintenance plan and for which EPA 
believes it is reasonable to interpret the Clean Air Act's reasonable 
further progress and attainment demonstration requirements so as not to 
require areas that are meeting the ozone standard to make certain SIP 
submissions. In addition, some subpart 1 areas may also be eligible for 
the clean data policy if they are required to submit control strategy 
SIPs. Areas that qualify for EPA's clean data policy

[[Page 40020]]

under the 8-hour standard can use one of the following three options to 
complete regional emissions analyses:
     The interim emissions tests, as described above;
     the budget test using the adequate or approved motor 
vehicle emissions budgets in an 8-hour ozone SIP; or
     the budget test using the motor vehicle emissions levels 
in the most recent year of clean data as budgets, if the state or local 
air quality agency requests that budgets be established by EPA's clean 
data rulemaking for the 8-hour ozone standard and EPA approves the 
request.

As stated in Phase 1 of EPA's final 8-hour ozone implementation rule 
(April 30, 2004, 69 FR 23974), EPA intends to extend the existing clean 
data policy to applicable 8-hour ozone areas, and will respond on this 
issue in its future Phase 2 final 8-hour ozone implementation rule.
    Please note that EPA's clean data policy, and therefore today's 
provision allowing emissions in the most recent year of clean data to 
be used as a budget, might not be available in any area for the first 
8-hour conformity determination. Newly designated areas may not yet 
have three years of clean data for the 8-hour standard when the first 
conformity determination is due for that standard. As discussed in 
Section III., the first plan/TIP conformity determination is due by 
June 15, 2005, one year after the effective date of 8-hour 
designations.
4. General Implementation of Regional Tests
    Regional emissions analyses for ozone areas must address both ozone 
precursors, which are nitrogen oxides (NOX) and volatile 
organic compounds (VOCs) (40 CFR 93.102(b)(2)(i)). Before budgets are 
available, areas must meet the appropriate interim emissions test(s) 
for both VOC and NOX precursors, unless EPA issues a 
NOX waiver for the 8-hour standard under Clean Air Act 
section 182(f). This provision is consistent with the conformity rule 
to date, although in today's final rule the NOX waiver 
provision is moved to Sec.  93.119(f) (from Sec.  93.119(d)) because of 
the reorganization of Sec.  93.119. Once an adequate or approved SIP 
budget is available for the 8-hour standard, it must be used for 
regional emissions analyses.
    In general, if a budget is available for only one ozone precursor, 
the interim emissions test(s) will continue to apply for the other 
precursor. For example, this situation would occur when a reasonable 
further progress SIP is submitted with a budget for VOCs only (e.g., a 
15% SIP), and this case is specifically covered by Sec.  93.109(d)(3). 
In this example, an area would use the budget test for VOCs and the 
interim emissions test(s) for NOX, unless it has a 
NOX waiver as described above.
    The consultation process must be used to determine the models and 
assumptions for completing either the interim emissions tests or the 
budget test, as required by Sec.  93.105(c)(1)(i) of the current rule.

B. Rationale and Response to Comments

    The use of the budget test once budgets are available for an air 
quality standard is based on the requirements of the Clean Air Act. 
Once budgets have been found adequate or approved, the budget test 
provides the best means to determine whether transportation plans and 
TIPs conform to a SIP and complies with the statutory obligation to be 
consistent with the emissions estimates in SIPs, according to Clean Air 
Act section 176(c)(2)(A). Several commenters specifically agreed that 
once a SIP for the 8-hour ozone standard is submitted with a budget(s) 
that EPA has found adequate or approved, the budget test should be 
used. One of these commenters stated that the advantage of the budget 
test is that areas have a high degree of confidence in attaining and 
maintaining the standards if emissions are held to budget levels from 
SIPs demonstrating attainment and maintenance. Another of these 
commenters strongly supported establishing 8-hour budgets through the 
submission of early SIPs, as discussed above.
    Before budgets are available, the final rule's interim emissions 
test requirements for 8-hour areas are generally consistent with 
requirements for 1-hour areas. In general, several commenters supported 
the flexibility provided by the test options for 8-hour marginal and 
subpart 1 areas that do not have 1-hour ozone SIPs.
    EPA believes that it is reasonable and credible to provide 8-hour 
ozone areas that are not classified moderate or above the same 
flexibility that applies under the 1-hour ozone standard. Several 
commenters specifically supported allowing these 8-hour ozone areas a 
choice between the baseline year and build/no-build tests. EPA 
determined in the 1997 conformity rule that either test could satisfy 
the statutory test of not causing or contributing to violations or 
delaying attainment in these areas, and the Agency believes this would 
continue to be true for new 8-hour areas, as discussed further below.
    A few commenters requested clarification that the interim emissions 
test options remain available in subsequent conformity determinations 
until adequate or approved budgets are in place. These commenters are 
correct that while no 8-hour ozone budgets are available, areas are 
free to choose either test for a conformity determination, regardless 
of what test was used for a prior conformity determination. For 
example, if an MPO within a marginal 8-hour nonattainment makes a 
conformity determination based on the build-no-greater-than-no-build 
test, this would not preclude them, prior to adequate or approved 
budgets, from making a future conformity determination based on the no-
greater-than-2002 emissions test. However, under these final rules, the 
same test must be used for each analysis year for a given conformity 
determination. In other words, an MPO may not use the build-no-greater-
than-no-build test in one analysis year and the no-greater-than-2002 
test in another analysis year within the same conformity determination. 
EPA believes that sufficient flexibility exists without mixing and 
matching interim emissions tests for different analysis years within 
one conformity determination, which is unnecessarily complicated and 
suggests that the area would not conform using one test consistently.
    One commenter advocated that state air agencies should have the 
authority to determine which test is used, because in the commenter's 
view the state air agency would best be able to choose the test that 
ensures progress towards attainment. However, EPA believes that it is 
appropriate for the decision to be made within the interagency 
consultation process, as has been done to date. Given that MPOs have 
responsibility for making the conformity determination, and would need 
to set up the no-build network if the build-no-greater-than-no-build 
test is used, EPA believes they need to take part in choosing the test. 
State air agencies are insured a role in the transportation conformity 
process through interagency consultation, as Sec.  93.105 of the 
conformity rule sets forth the requirements for state air agencies' 
participation in the conformity process, as well as a process for 
resolving conflicts. The state air agency role is also addressed in the 
preamble to the 1993 rule (November 24, 1993, 58 FR 62201). EPA 
continues to believe that the conflict resolution process provides a 
mechanism for the state air agency to elevate issues to the governor if 
they cannot be resolved by state agency officials, and that the process 
facilitates collaboration which is essential to

[[Page 40021]]

cooperative transportation and air quality planning. Therefore, EPA is 
not changing the final rule in response to this comment.
    A few commenters supported one or the other of the proposed interim 
emissions tests in 8-hour marginal or subpart 1 areas. One commenter 
supported elimination of the build-no-greater-than-no-build test 
because no specific allowable level or limit is placed on emissions 
levels associated with the no-build scenario, while the no-greater-
than-2002 test compares future emissions to a specified allowable 
level. However, another commenter made an opposing argument against the 
use of the no-greater-than-2002 test arguing that if an area was not 
attaining the 8-hour ozone standard in 2002, then the no-greater-than-
2002 test allows emissions to continue at a level that will not bring 
the area into attainment. A third commenter suggested that prior to 
adequate or approved SIP budgets, emissions should be held to as low a 
level as possible to prevent an area from proceeding with 
transportation projects that may preclude them from meeting the 8-hour 
ozone standard in the future.
    Since the transportation conformity rule was promulgated on 
November 24, 1993 (58 FR 62188), the build-less-than-no-build and less-
than-1990 tests have been part of the transportation conformity rule as 
appropriate tests in meeting the conformity requirements of the Clean 
Air Act prior to the availability of SIP budgets. In the August 15, 
1997 amendments (62 FR 43780), the transportation conformity rule was 
amended to allow ozone areas not classified moderate or higher to meet 
either the build-less-than-no-build test or the no-greater-than-1990 
test. Our rationale for this change is found in the proposed rulemaking 
for those amendments (July 9, 1996, 61 FR 36112).
    Though EPA has updated the tests in today's rule, our rationale for 
allowing 8-hour marginal and subpart 1 areas to choose between the two 
tests remains the same as described in the 1996 proposal. When there 
are no adequate or approved budgets, EPA believes that either test 
meets the Clean Air Act requirement that transportation activities will 
not cause new violations, increase the frequency or severity of 
existing violations, or delay timely attainment. In contrast to ozone 
areas of higher classifications, transportation activities in these 
areas are not required to contribute to emissions reductions per Clean 
Air Act section 176(c)(3)(A)(iii).
    Though EPA considered additional options for moderate and above 8-
hour ozone areas as discussed in Section IV.D., the final rule is 
consistent with requirements for 1-hour ozone areas. In 8-hour 
nonattainment areas classified moderate or above, EPA believes the 
build-less-than-no-build and the less-than-2002 tests together support 
the determination that a transportation plan, TIP, or project will not 
cause new violations, increase the frequency or severity of existing 
violations, or delay attainment. In addition, these tests together 
demonstrate that plans and TIPs contribute to emissions reductions 
required by section 176(c)(3)(A)(iii) of the Clean Air Act. Additional 
discussion of the rationale for both tests in these areas is also found 
in Section IV.D.
    EPA is also continuing to provide more choices to areas that 
qualify for EPA's clean data policy. As EPA intends to include the 
clean data policy in EPA's Phase 2 final 8-hour ozone implementation 
rule, EPA is including the conformity options for such areas in today's 
conformity rule. These provisions will be able to be used once EPA has 
found that an area is a clean data area for the 8-hour standard 
pursuant to the regulations the Agency intends to promulgate under 
Phase 2 of the 8-hour implementation rule. See EPA's previous 
discussion and rationale for the conformity clean data options from the 
preamble to the 1996 proposed and 1997 final transportation conformity 
rule amendments (July 9, 1996, 61 FR 36116; and August 15, 1997, 62 FR 
43784-43785, respectively). Two commenters supported extending the 
clean data policy to qualifying 8-hour ozone areas. One reasoned that 
conformance with budgets constrained by emissions levels during years 
in which the area demonstrated attainment should not cause or 
contribute to nonattainment, and thus meeting any one of the tests for 
clean data areas should be sufficient to demonstrate conformity.
    However, two commenters stated that EPA should not apply a ``clean 
data policy'' to ozone areas classified as moderate or above because 
Clean Air Act sections 172 and 175A require a completed SIP containing 
measures that must be implemented if the area backslides into 
nonattainment, and a maintenance plan if the area seeks to avoid 
implementing some elements of its nonattainment plan.
    In today's final rule, EPA is not making changes to its existing 
clean data policy, nor to the conformity process for clean data areas. 
EPA is merely extending the conformity flexibility that 1-hour ozone 
clean data areas have to the 8-hour ozone clean data areas. EPA 
believes this is appropriate since the Agency intends to extend the 
clean data policy to 8-hour areas for SIP purposes in Phase 2 of the 
final 8-hour ozone implementation rule. EPA will respond to all 
comments on the appropriateness of that extension in the final action 
on Phase 2 of the final 8-hour implementation rule.
    Finally, one commenter wanted EPA to issue VOC waivers for areas 
that are NOX limited, so they can focus on getting 
NOX reductions. However, though section 182(f) of the Clean 
Air Act specifically provides that EPA could waive NOX 
requirements in certain areas, the Clean Air Act provides no such 
flexibility with respect to VOCs. Since VOCs are clearly an ozone 
precursor, ozone areas must demonstrate conformity to VOC levels that 
provide for attainment and maintenance to prevent potential future 
violations, even in areas that may not need additional VOC reductions 
to attain. EPA has no ability to offer any provision to give areas VOC 
waivers.

VI. Regional Conformity Tests in 8-Hour Ozone Areas That Have 1-Hour 
Ozone SIPs

A. Description of Final Rule

    This section covers how regional emissions analyses must be done in 
8-hour ozone areas with an existing 1-hour ozone SIP that covers either 
part or all of the 8-hour ozone nonattainment area. The regulatory text 
in Sec.  93.109(e) provides a general overview of when the budget test 
and interim emissions tests apply in 8-hour ozone nonattainment areas 
with adequate or approved 1-hour ozone SIP budgets. As in Section V., 
EPA describes the final rule provisions in four parts: conformity when 
8-hour budgets are available, conformity before 8-hour budgets are 
available, conformity in clean data areas, and general implementation 
of regional emissions tests.

1. Conformity After 8-Hour Ozone SIP Budgets Are Adequate or Approved

    Once a SIP for the 8-hour ozone standard is submitted with 
budget(s) that EPA has found adequate or approved, the budget test with 
the budgets from the 8-hour ozone SIP must be used in accordance with 
Sec.  93.118 to complete the regional emissions analysis for 8-hour 
conformity determinations. The first 8-hour ozone SIP could be a 
control strategy SIP required by the Clean Air Act (e.g., rate-of-
progress SIP or attainment demonstration). The first SIP could also

[[Page 40022]]

be submitted earlier and demonstrate a significant level of emission 
reductions from the current level of emissions, as described in Section 
V.A.1. Any existing 1-hour ozone SIP budgets and/or interim emissions 
tests will no longer be used for conformity for either NOX 
or VOCs once an adequate or approved 8-hour SIP budget is established 
for such a precursor. State, local, and federal air quality and 
transportation agencies must consult on the development of 8-hour ozone 
SIPs including their budgets as appropriate, pursuant to Sec.  93.105 
of the conformity rule.

2. Conformity Before 8-Hour Ozone SIP Budgets Are Adequate or Approved

    Under today's final rule, all 8-hour areas with adequate or 
approved 1-hour budgets must use these budgets for 8-hour conformity 
before 8-hour budgets are available, unless it is determined through 
the interagency consultation process that using the interim emissions 
tests is more appropriate for meeting Clean Air Act requirements. In 
today's rule, the budget test using the existing 1-hour ozone SIP 
budgets fulfills the regional emissions analysis requirement for the 8-
hour ozone standard, rather than the 1-hour ozone standard. Please note 
that the 1-hour budgets are to be used as a proxy for 8-hour budgets. 
Conformity for the 1-hour and 8-hour ozone standards will not apply at 
the same time, according to EPA's April 30, 2004 final 8-hour ozone 
implementation rule, as described in Section III. of today's action.
    There are four potential scenarios into which areas covered by this 
section can be categorized:
     Scenario 1: Areas where the 8-hour ozone area boundary is 
exactly the same as the 1-hour ozone area boundary;
     Scenario 2: Areas where the 8-hour boundary is smaller 
than the 1-hour boundary, (i.e., the 8-hour area is completely within 
the 1-hour area);
     Scenario 3: Areas where the 8-hour boundary is larger than 
the 1-hour boundary (i.e., the 1-hour area is completely within the 8-
hour area); and
     Scenario 4: Areas where the 8-hour boundary partially 
overlaps the 1-hour area boundary.

EPA has posted diagrams of these four boundary scenarios for further 
clarification on the transportation conformity Web site. Please note 
that scenarios are determined according to how the entire 8-hour 
nonattainment area relates to the entire 1-hour nonattainment or 
maintenance area(s). For example, in a multi-state 8-hour area, the 
area's scenario and corresponding conformity requirements are based on 
the entire 8-hour area boundary, rather than on each state's portion of 
the 8-hour area. State and local agencies can consult with EPA and DOT 
field offices to determine which scenario applies to a given 8-hour 
nonattainment area.
    The following paragraphs describe how regional conformity tests are 
applied in the four boundary scenarios, as well as the circumstances 
under which another test(s) may be appropriate. Please see A.4. of this 
section for further information regarding when another test may be 
appropriate for meeting Clean Air Act requirements. EPA will post more 
detailed implementation guidance on its transportation conformity 
website for conformity determinations in new standard areas, including 
8-hour ozone areas with 1-hour SIP budgets and multi-state/multi-MPO 
nonattainment areas. Please also see Section I.B.2. of this notice for 
information regarding EPA's conformity Web site.
    Scenario 1: Areas where 8-hour and 1-hour ozone boundaries are 
exactly the same. In this case, the 8-hour and 1-hour ozone boundaries 
cover exactly the same geographic area. Such an area could be formed 
from a single 1-hour area, or more than one 1-hour area, as long as the 
entire 8-hour area boundary is exactly the same as the boundary of the 
previous 1-hour area or areas.
    In these areas, conformity must generally be demonstrated using the 
budget test according to Sec.  93.118 with the 1-hour SIP budgets, as 
described in A.4. of this section. The regulatory text in Sec.  
93.109(e)(2)(i) covers Scenario 1 areas. The interagency consultation 
process would be used to clarify the 1-hour budget(s) for the 8-hour 
area. The interim emissions test(s) would only be used if it is 
determined through the consultation process that an adequate or 
approved 1-hour budget is not appropriate for a given year(s) in a 
regional emissions analysis, as explained in A.4. of this section and 
Sec.  93.109(e)(2)(v) of the final rule. EPA will post on its website 
implementation guidance for conducting 8-hour conformity determinations 
in multi-jurisdictional areas, including Scenario 1 areas with multiple 
states, MPOs, etc. Please see Section I.B.2. of this notice for 
information regarding EPA's conformity website.
    Scenario 2: Areas where the 8-hour ozone boundary is smaller than 
and within the 1-hour ozone boundary. In this case, the 8-hour 
nonattainment area is smaller than and completely encompassed by the 1-
hour nonattainment boundary. In these areas, conformity must generally 
be shown using one of the following versions of the budget test:
     The budget test using the subset or portion(s) of existing 
adequate or approved 1-hour ozone SIP budgets that cover the 8-hour 
nonattainment area, where such portion(s) can be appropriately 
identified; or
     The budget test using the existing adequate or approved 1-
hour ozone SIP budgets for the entire 1-hour nonattainment area. 
However, in this case any additional emissions reductions beyond those 
addressed by control measures in the 1-hour SIP budgets need to pass 
the budget test and must come from within the 8-hour nonattainment 
area.

The budget test would be completed according to the requirements in 
Sec.  93.118, as described in A.4. of this section. The regulatory text 
in Sec.  93.109(e)(2)(ii)(A) and (B) reflects these two choices. Though 
the November 5, 2003 proposed rule included both choices in one 
paragraph, today's rule separates them into different regulatory 
subparagraphs simply for ease of readability.
    Once an area selects either of these budget test options, it must 
be used consistently for each analysis year of a given conformity 
determination. EPA believes that to do otherwise would be unnecessarily 
complicated and would imply that one test option used consistently for 
all analysis years may not demonstrate conformity. The interim 
emissions test(s) would only be used if it is determined through the 
consultation process that an adequate or approved 1-hour budget is not 
appropriate for a given year(s) in the regional emissions analysis, as 
explained in A.4. of this section and Sec.  93.109(e)(2)(v) of the 
final rule.
    As described in the November 2003 proposal, the first budget test 
option is available to an area if it is possible to determine what 
portion of the 1-hour budget applies to the 8-hour area. In that case, 
that portion can be used as the budget for the 8-hour area. Determining 
such a budget would be straightforward, for example, if the budget 
corresponds directly with an on-road mobile inventory for the 1-hour 
ozone SIP that was calculated by county, and the portion to be 
subtracted is a specific county that is not part of the 8-hour ozone 
area. However, where the 1-hour SIP does not clearly specify the amount 
of emissions in the portion of the 1-hour ozone area not covered by the 
8-hour ozone area, this method may not be available. The consultation 
process would be used to determine whether using a portion of a 1-hour 
ozone SIP

[[Page 40023]]

budget is appropriate and feasible, and if so, how deriving such a 
portion would be accomplished.
    In the second budget test option, a conformity determination based 
on the entire 1-hour ozone budget would include a comparison between 
the on-road regional emissions produced in the entire 1-hour ozone area 
and the existing 1-hour ozone budgets. However, if additional emissions 
reductions are required to meet conformity beyond those produced by 
control measures in the 1-hour SIP budgets, only reductions within the 
8-hour ozone nonattainment area can be included in the regional 
emissions analysis. If conformity cannot be determined on schedule 
using either budget test option, only the 8-hour ozone nonattainment 
area would be in a conformity lapse.
    Scenario 3: Areas where the 8-hour ozone boundary is larger than 
the 1-hour ozone boundary. This scenario will result when an entire 1-
hour ozone nonattainment or maintenance area is contained within a 
larger 8-hour ozone area. For example, a Scenario 3 area would result 
when an 8-hour area is formed from an existing 1-hour area plus an 
additional county or counties that were not covered by the 1-hour 
standard. In these areas, the budgets from the previous 1-hour ozone 
area will not cover the entire 8-hour nonattainment area. However, 
conformity must consider regional emissions for the entire 8-hour ozone 
nonattainment area.
    Therefore, in these areas, conformity must generally be 
demonstrated using the budget test based on the 1-hour ozone SIP 
budgets for the 1-hour ozone area, plus the interim emissions test(s) 
for one of the following:
     The portion of the 8-hour ozone nonattainment area not 
covered by the 1-hour budgets;
     The entire 8-hour ozone nonattainment area; or
     The entire portion of the 8-hour ozone nonattainment area 
within an individual state, in the case where 1-hour SIP budgets are 
established for each state in a multi-state nonattainment area.

The budget test would be completed according to the requirements in 
Sec.  93.118, as described in A.4. of this section. The interim 
emissions tests would only be used instead of the 1-hour budget if it 
is determined through the consultation process that an adequate or 
approved 1-hour budget is not appropriate for a given year in the 
regional emissions analysis, as explained in A.4. of this section and 
Sec.  93.109(e)(2)(v) of the final rule. The regulatory text in Sec.  
93.109(e)(2)(iii)(A) and (B) reflects requirements for Scenario 3 
areas. EPA notes that the final rule separates Scenario 3 and 4 area 
test requirements in the regulation for easier implementation.
    The final rule's options for interim emissions tests are intended 
to give areas the flexibility to continue to implement conformity as 
they have under the 1-hour standard. EPA is clarifying this flexibility 
related to multi-state areas in the final rule since it was intended by 
the proposal and supported by public comments received.
    For example, if an 8-hour multi-state nonattainment area with 
multiple MPOs has separate adequate or approved 1-hour budgets for each 
state, the MPOs would continue to determine conformity to their state's 
1-hour budgets. In this special case where states and MPOs want to 
continue to work independently under the 8-hour standard, the budget 
test would be completed with applicable 1-hour SIP budgets for each 
state. In addition, the interim emissions test(s) would be done for 
either:
     any portion of a state's 8-hour nonattainment area that is 
not covered by a state's 1-hour SIP budget; or
     the entire portion of the 8-hour nonattainment area 
covered by that state.

EPA notes that the interim emissions test(s) could also be done for the 
entire 8-hour nonattainment areas under this final rule in this 
example. However, doing so may not allow each MPO in this example to 
develop transportation plans and TIPs and conformity determinations 
independently.
    Rather than include all the possibilities of this type and others 
in today's preamble, EPA will post implementation guidance on its 
transportation conformity Web site for conducting 8-hour conformity 
determinations with 1-hour SIP budgets, including determinations in 
multi-state and multi-MPO nonattainment areas. Please see Section 
I.B.2. of this notice for information regarding EPA's conformity Web 
site. In any case, whether one or both interim emissions tests is 
required depends on the area's classification or whether an area is a 
subpart 1 area, as described in Section V. of today's preamble.
    EPA acknowledges that there may be cases where it is difficult to 
model the remaining portion of the 8-hour ozone area separately, e.g., 
in an area where the remaining 8-hour ozone area is a ring of counties 
around the 1-hour ozone area. In this case, an area may choose to 
complete the interim emissions test(s) for the entire 8-hour ozone 
area, rather than just the portion not covered by the 1-hour ozone 
budgets. Once an area selects a particular interim emissions test(s) 
and geographic coverage for such test(s), these choices must be applied 
consistently for all regional analysis years in a given conformity 
determination. For example, a marginal 8-hour ozone area that is larger 
than the 1-hour ozone area with one applicable 1-hour SIP can complete 
the regional emissions analysis by meeting the budget test for the 1-
hour ozone nonattainment area and the no-greater-than-2002 test for the 
remaining portion of the 8-hour ozone area for all analysis years.
    The consultation process should also be used to select analysis 
years for performing modeling where both the budget test (Sec.  93.118) 
and interim emissions test(s) (Sec.  93.119) are used. Sections 
93.118(d) and 93.119(g) of the conformity rule both require the last 
year of the transportation plan and an intermediate year(s) to be 
analysis years where modeling is completed. However, the analysis years 
for the short-term may be different for the budget test and interim 
emissions tests in some cases. For example, Sec.  93.118 requires 
modeling for the budget test to be completed for the attainment year if 
it is within the timeframe of the transportation plan; Sec.  93.119 
requires the first analysis year for the interim emissions tests to be 
within the first five years of the transportation plan. The 
consultation process can be used to select analysis years that satisfy 
both the budget and interim emissions test requirements as appropriate 
to avoid multiple modeling analyses in these cases.
    Scenario 4: Areas where the 8-hour ozone boundary overlaps with a 
portion of the 1-hour ozone boundary. This scenario results when 1-hour 
and 8-hour boundaries partially overlap. For example, a Scenario 4 area 
could be an 8-hour area formed from a portion of one or more 1-hour 
areas plus new counties that were not covered by the 1-hour standard. 
As in the previous scenarios, these areas must generally use existing 
1-hour budgets whenever feasible to determine conformity, plus the 
interim emissions test(s) when a portion of the 8-hour nonattainment 
area is not covered by existing 1-hour budgets.
    In Scenario 4 areas, conformity must generally be demonstrated 
using the budget test based on the portion of the 1-hour ozone SIP 
budget(s) that covers both the 1-hour and 8-hour areas, plus

[[Page 40024]]

the interim emissions test(s) for one of the following:
     The portion of the 8-hour ozone nonattainment area not 
covered by the portion of the 1-hour budgets;
     the entire 8-hour ozone nonattainment area; or
     the entire portion of the 8-hour ozone nonattainment area 
within an individual state, in the case where separate 1-hour SIP 
budgets are established for each state in a multi-state nonattainment 
area.

EPA has also clarified in the regulatory text that only the budget test 
would be completed in the limited case where portions of 1-hour SIP 
budgets cover the entire 8-hour nonattainment area or portions thereof. 
Whatever the case, the budget test would be completed according to the 
requirements in Sec.  93.118, as described in A.4. of this section. The 
regulatory text in Sec.  93.109(e)(2)(iv)(A) and (B) reflect Scenario 4 
area requirements. EPA again notes that the final rule separates 
Scenario 3 and 4 area test requirements for easier implementation.
    The interim emissions tests would be used instead of a 1-hour 
budget only if it is determined through the consultation process that 
an adequate or approved 1-hour budget is not appropriate for a given 
year in the regional emissions analysis, or if it is not possible to 
determine what portion of the 1-hour budgets apply to the 8-hour area, 
as described in A.4. of this section and Sec.  93.109(e)(2)(v) of the 
final rule.
    As described for Scenario 3 above, the final rule is intended to 
give areas the flexibility to continue to implement conformity as they 
have under the 1-hour standard. EPA will post implementation guidance 
on its transportation conformity Web site for conformity determinations 
in Scenario 4 and other 8-hour areas. Please see Section I.B.2. of this 
notice for information regarding EPA's conformity Web site.
    As described for Scenario 3, the consultation process should be 
used to select the analysis years where both the budget test (Sec.  
93.118) and interim emissions test(s) (Sec.  93.119) are used. It 
should be possible to choose analysis years in most cases that satisfy 
both the budget and interim emissions test requirements for areas using 
both tests. Whether one or both interim emissions tests is required in 
any case depends on the area's classification or whether an area is a 
subpart 1 area, as described in Section V. of today's preamble.
3. Options for 8-Hour Ozone Areas That Qualify for EPA's Clean Data 
Policy
    As described in Section V.A.3., EPA is extending the conformity 
rule's flexibility for 1-hour ozone ``clean data areas'' to 8-hour 
ozone areas that meet the criteria of the clean data policy. Clean data 
areas for the 8-hour ozone standard with adequate or approved 1-hour 
ozone SIP budgets must generally use one of the following three options 
to complete conformity:
     The budget test using the adequate or approved motor 
vehicle emissions budgets in a SIP for the 8-hour ozone standard;
     The budget and/or interim emissions tests using existing 
1-hour ozone SIP budgets and/or applicable interim emissions tests, as 
described in A.2. of this section for different scenarios of 1-hour and 
8-hour ozone nonattainment boundaries; or
     The budget test using the motor vehicle emissions level in 
the most recent year of clean data as budgets, if such budgets are 
established by the EPA rulemaking that determines an area to have clean 
data for the 8-hour ozone standard.

See the regulatory text for these options in Sec.  93.109(e)(4), and 
preamble Section V.A.3. for more information about clean data areas.
4. General Implementation of Regional Tests
    Under the existing conformity rule, regional emissions analyses for 
ozone areas must address NOX and VOC precursors (40 CFR 
93.102(b)(2)(i)). Areas must also complete the interim emissions 
test(s) for NOX as required by Sec.  93.119 if the only SIP 
available is a reasonable further progress SIP for either the 1-hour or 
8-hour standard that contains a budget for VOCs only (e.g., a 15% SIP). 
In all cases where areas use the interim emissions test(s), both 
precursors must be analyzed unless EPA issues a NOX waiver 
for the 8-hour standard for an area under Clean Air Action section 
182(f). This is consistent with the conformity rule to date, although 
today's final rule moves these provisions to Sec.  93.119(f) due to 
reorganization of Sec.  93.119. See Sec.  93.109(e)(3) for this 
regulatory text.
    The consultation process must be used to determine the models and 
assumptions for completing the budget test and/or the interim emissions 
test(s), as required by Sec.  93.105(c)(1)(i) of the rule. The 
consultation process must also be used to decide if the interim 
emissions test(s) are more appropriate to meet the Clean Air Act 
requirements than existing adequate or approved 1-hour budgets before 
8-hour ozone SIPs are submitted.
    General implementation of the budget test with 1-hour budgets. The 
budget test requirements in Sec.  93.118 for 8-hour areas will be 
generally implemented in the same manner as in 1-hour areas, with a few 
exceptions. First, as described above, the geographic area covered by 
the 8-hour standard may be different than that covered by the 1-hour 
standard and SIP budgets in some cases. Second, the years for which 
regional modeling is performed will slightly differ.
    Areas that use 1-hour budgets for their 8-hour conformity 
determinations will need to determine the modeling analysis years that 
apply for the 8-hour standard per Sec.  93.118(d). Under this section, 
a modeling analysis must be completed for the last year of the 
transportation plan, the attainment year for the relevant pollutant and 
standard, and an intermediate year(s) such that analysis years are not 
more than 10 years apart. The attainment year analysis is to be for an 
area's attainment year for the 8-hour standard, which will be different 
than the attainment year under the 1-hour standard. The area must then 
calculate emissions in the analysis years from the existing and planned 
transportation system.
    Once modeling is completed per Sec.  93.118(d)(2), 8-hour areas 
using 1-hour SIPs will also demonstrate consistency with 1-hour SIP 
budgets according to Sec.  93.118(b), except for cases where it is 
determined that 1-hour SIP budgets are not appropriate through the 
consultation process as described above. According to Sec.  93.118(b) 
of today's final rule as described in Section XXIII., consistency with 
1-hour budgets must be shown for all 1-hour budget years that are 
within the timeframe of the transportation plan, the 8-hour attainment 
year (if in the timeframe of the plan), the last year of the plan, and 
an intermediate year(s) so that all years are not more than 10 years 
apart. Emissions projected for each analysis year must be within the 
budgets in the 1-hour SIP from the most recent prior year. 
Interpolation can be used between analysis years for demonstrating 
consistency with budgets, just as has been done under the 1-hour 
standard.
    For example, suppose an area designated nonattainment for the 8-
hour ozone standard with an 8-hour attainment date of 2010 has the 
following 1-hour SIP budgets:
     2005 rate-of-progress budgets for NOX and 
VOCS,
     2007 rate-of-progress budgets for NOX and 
VOCS, and

[[Page 40025]]

     2007 attainment demonstration budgets for NOX 
and VOCS.
    By 2005, this area would determine conformity for its 2005-2025 
transportation plan and its TIP, and the conformity determination would 
be accomplished as follows:
     2005 budget test, using the 2005 ROP budgets;
     2007 budget test, using both 2007 ROP and attainment 
budgets;
     2010 budget test, using the 2007 attainment budgets; \12\
---------------------------------------------------------------------------

    \12\ EPA has previously interpreted that only attainment budgets 
apply beyond the attainment year, in cases where ozone areas also 
have budgets for rate-of-progress SIPs.
---------------------------------------------------------------------------

     2020 budget test, using the 2007 attainment budgets; and
     2025 budget test, using the 2007 attainment budgets.
    As described in Sec.  93.118(d)(2), emissions for the year 2005 
could be generated with a regional emissions analysis, or could be 
interpolated if the area has run a regional emissions analysis for an 
earlier year. Emissions for the year 2007 can also be interpolated or 
the area could choose to model emissions for this year. A regional 
modeling analysis must be done for the year 2010 (the 8-hour attainment 
year), any year between 2015 and 2020 for the intermediate year (in the 
above example, 2020 is the intermediate year), and the year 2025 (the 
last year of the transportation plan) as required by Sec.  
93.118(d)(2).
    As stated in A.1. of this section, once adequate or approved 8-hour 
SIP budgets are established for a given precursor, the budget test 
would be completed with only the 8-hour SIP budgets for that precursor, 
rather than the 1-hour SIP budgets.
    When might 1-hour SIP budgets not be the most appropriate test for 
8-hour ozone conformity? Though EPA anticipates that exceptions to the 
use of the 1-hour budgets will be infrequent, there are some cases 
where using another test(s) may be more appropriate to meet Clean Air 
Act requirements. EPA expects such limited cases to be supported and 
documented in the 8-hour conformity determination for a given area. EPA 
notes that an adequate or approved 1-hour SIP budget cannot be 
considered inappropriate simply because it is difficult to pass for 8-
hour conformity purposes. In addition, as noted below and consistent 
with past conformity precedent, 1-hour SIP budgets cannot be discarded 
simply because they are based on older planning assumptions or 
emissions models, unless through interagency consultation it is 
determined that a different emissions test(s) is more appropriate to 
ensure that air quality is not worsened for all 8-hour areas and that 
reductions are achieved in certain ozone areas.
    The most likely example of when the budgets may not be the most 
appropriate test is where a 1-hour SIP budget is not currently used in 
conformity determinations for the 1-hour standard, and thus is 
currently not relied upon to measure whether transportation activities 
are consistent with Clean Air Act requirements. Such a case would 
happen when the SIP budget year is no longer in the timeframe of the 
transportation plan and there is no requirement to meet the budget test 
prior to the year in which the next 1-hour SIP budget is established 
(e.g., the SIP established a budget for the 1-hour attainment year, but 
that attainment year has passed and budgets for future years are 
available).
    For example, suppose a 1-hour maintenance area attained in 1999 and 
has a maintenance plan with budgets for 2009. If the area has an 8-hour 
attainment date of 2007, it would have to compare emissions in 2007 to 
the budgets from the most recent prior year, which would be the 
attainment budgets for the year 1999. In this case, the budgets are not 
currently in use for the 1-hour standard, and it may be more 
appropriate for an area to use the 2002 baseline year test for the 2007 
analysis year, since the 2002 baseline could be lower and therefore 
more protective than the 1999 budgets. However, the maintenance area 
would use its 2009 budgets in the 1-hour maintenance plan to show 8-
hour conformity for 2009 and all future analysis years.
    Another example of when another test would be more appropriate than 
existing adequate or approved 1-hour SIP budgets would be in certain 
Scenario 4 areas where it is impossible to determine which portion of a 
1-hour SIP budget covers an 8-hour nonattainment area. In this case, 
applying the budget test with 1-hour SIP budgets is not feasible, and 
consequently, only the interim emissions test(s) are available for such 
unique areas.
    As described in Section V., when a SIP budget is not established a 
moderate or above ozone area would need to pass both interim emissions 
tests. Areas classified as marginal or designated under Clean Air Act 
subpart 1 can choose between the two tests when no budgets apply. 
However, in these cases where a 1-hour budget is available but the area 
demonstrates it is not the most appropriate test, EPA believes that the 
no-greater-than-2002 baseline year test would most likely be used. EPA 
believes it is extremely unlikely that the build/no-build test alone 
would ever be a more appropriate test than the budget test with 
existing 1-hour SIP budgets that are currently used for conformity 
purposes. See B.2. of this section below for further information 
regarding EPA's rationale for using 1-hour budgets and what is 
appropriate for meeting Clean Air Act requirements.
    Areas must use the consultation process to decide whether the 
applicable interim emissions tests are more appropriate to meet Clean 
Air Act requirements than the 1-hour budgets, pursuant to Sec.  
93.109(e)(2)(v) of the final rule. In areas where another test(s) is 
used, areas must also justify selection of the specific test(s) chosen 
as being more appropriate for meeting Clean Air Act requirements than 
the available 1-hour SIP budgets. This decision should be discussed 
with all interagency consultation parties and documented in the 
conformity determination for the 8-hour standard.

B. Rationale and Response to Comments

1. Conformity After 8-Hour Ozone SIP Budgets Are Adequate or Approved
    Several commenters strongly supported establishing budgets for the 
8-hour standard through the submission of early SIPs. EPA agrees that 
Clean Air Act section 176(c) is met when the budget test is used, once 
budgets are available for an air quality standard. Once 8-hour ozone 
budgets have been found adequate or approved, the budget test provides 
the best means to determine whether transportation plans and TIPs 
conform to an 8-hour ozone SIP and comply with the statutory obligation 
to be consistent with the emissions estimates in SIPs, according to 
Clean Air Act section 176(c)(2)(A). A few commenters suggested that EPA 
urge states to establish budgets for the 8-hour standard early because 
of the potential complications without 8-hour budgets where the 8-hour 
boundary differs from the 1-hour boundary. EPA agrees that state and 
local agencies can choose to establish an early SIP for conformity 
purposes, however, each area needs to consider the benefits of an early 
SIP and impacts on state and local resources.
    One commenter suggested that ozone areas should be required to 
consider emissions in the portion of the 8-hour area that is outside 
the boundary of the 1-hour standard when developing 8-hour SIPs. EPA 
agrees. In fact, they are required to consider these emissions because 
the SIP addressing the 8-hour standard must cover the entire 8-hour

[[Page 40026]]

nonattainment area. Please note that the conformity rule does not 
change existing SIP requirements and policy that will apply for the new 
standards.
    Another commenter recommended that once 8-hour budgets are adequate 
or approved, areas should do conformity to both the 1-hour and the 8-
hour standards. The commenter believed that doing conformity to both 
standards would not represent a significant hurdle. EPA has decided, 
however, to revoke the 1-hour standard when the 8-hour standard 
conformity grace period ends, one year after the effective date of 8-
hour area designations. Once the 1-hour standard is revoked, conformity 
will no longer apply for that standard as a matter of law. Conformity 
therefore will only apply for one ozone standard at a time. Please see 
Section III. for more information regarding the conformity grace period 
and revocation of the 1-hour standard.
2. Conformity Before 8-Hour Ozone SIP Budgets Are Adequate or Approved
    Though EPA proposed that areas could choose among several options 
before 8-hour budgets are available, today's rule requires the use of 
1-hour SIP budgets, where available and appropriate, as a direct result 
of consideration of all of the relevant comments received on this 
issue. Section 176(c) of the Clean Air Act requires that transportation 
activities may not cause new violations, increase the frequency or 
severity of existing violations, or delay timely attainment. Using 1-
hour budgets where available and appropriate ensures that air quality 
progress to date is maintained, air quality will not be worsened and 
attainment of the 8-hour standard will not be delayed because of 
emissions increases.
    Once EPA finds a budget adequate or approves the SIP that includes 
it, the budget test provides the best means to determine whether 
transportation plans and TIPs meet Clean Air Act conformity 
requirements. EPA now believes this principle applies with respect to 
the 1-hour budgets in 8-hour nonattainment areas as well: in most 
cases, EPA concludes that the 1-hour budgets are the best test for 
determining conformity to the 8-hour standard before 8-hour ozone 
budgets are available because the 1-hour budgets have led to current 
air quality improvements. A couple of commenters noted that attaining 
the 1-hour standard is a milestone toward attaining the 8-hour 
standard. Some commenters mentioned that most 1-hour budgets in major 
urban areas are appropriate to use, especially in serious and above 
ozone areas that have budgets that have recently been updated with the 
MOBILE6 emissions factor model.
    A number of commenters described how emissions could increase if 
areas use the interim emissions tests instead of their 1-hour budgets. 
Emissions could increase if areas use the 2002 baseline year test, 
commenters stated, because 2002 motor vehicle emissions are 
significantly higher than existing 1-hour budgets in many cases. 
Commenters provided an analysis of 2002 baseline emissions estimates 
compared to 1-hour ozone budget levels for 12 major metropolitan areas 
to illustrate that the 2002 motor vehicle emissions were significantly 
higher than the 1-hour budgets in these areas. For one major 
metropolitan area that had established MOBILE6-based attainment budgets 
for 2007, the 2002 baseline year test based on MOBILE6 would result in 
allowable VOC and NOX emissions increasing by 44% and 56%, 
respectively, above the budget levels for the 1-hour ozone attainment 
demonstration. A second commenter corroborated this finding with data 
that showed VOCs could increase 47% and NOX could increase 
33% if 2002 emissions were used instead of the area's attainment 
budgets. Commenters concluded that emissions from motor vehicles could 
increase anywhere from 10 to 50% of the 1-hour budgets, and because 
motor vehicles represent a quarter to a half of all emissions in most 
metropolitan areas, the total emissions in an airshed could increase to 
the point where areas cannot attain the 8-hour standard.
    Likewise, the build/no-build test could also lead to an increase in 
emissions over the 1-hour budgets and from current air quality 
progress, according to some commenters. Several commenters argued that 
the build/no-build test sets no meaningful limit on emissions growth 
because the test is satisfied as long as the build emissions are less 
than the no-build emissions, regardless of how much emissions increase 
in both the build and no-build cases.
    Commenters also wrote to EPA about the results of using interim 
emissions tests where budgets are available. Many were concerned with 
negative impacts on public health due to the increase in emissions that 
could occur, especially impacts on children. One commenter predicted it 
would be difficult for areas to adopt future measures sufficient to 
offset the emissions increases that could result, and that such 
measures would impose increased burden on other source sectors, such as 
industrial sources and small businesses.
    EPA found the evidence and the arguments presented by these 
commenters compelling, and we now believe that using the interim 
emissions tests would not fulfill the Clean Air Act conformity tests 
when appropriate 1-hour budgets are available. Some areas with 1-hour 
budgets have not yet attained the 1-hour standard, and the 8-hour 
standard is generally more stringent. In these areas, EPA believes that 
every additional ton of motor vehicle emissions allowed above the 1-
hour budgets could impact an area's ability to attain the 8-hour 
standard and necessitate additional control measures.
    Under today's rule, therefore, the interim emissions test(s) are 
only available if the circumstances warrant it, as determined through 
the interagency consultation process. EPA agrees with these commenters 
that the budget test is generally more protective of air quality and 
that the interim emissions tests do not meet sections 176(c)(1)(A) and 
(B) of the Clean Air Act when an appropriate 1-hour budget is 
available.
    Furthermore, today's final rule is consistent with EPA's historical 
precedent that the budget test with an adequate or approved SIP budget 
is more appropriate than the interim emissions tests. As we stated in 
our July 9, 1996, conformity proposal (61 FR 36115), when motor vehicle 
emissions budgets have been established by SIPs, they provide a more 
relevant basis for conformity determinations. The baseline year and the 
build/no-build tests are sufficient for demonstrating conformity when 
an area does not have a budget. EPA created these tests based on the 
language in Clean Air Act section 176(c)(3). They ensure that emissions 
do not increase above emissions in a recent year, and show that the 
transportation plan and TIP contribute to emissions reductions, where 
required. However, these tests usually do not ensure that 
transportation emissions promote progress toward the air quality 
standards to the same extent that the use of motor vehicle emissions 
budgets do. Although the 1-hour SIP budgets are for a different 
standard, they still address ozone, will help areas make progress 
toward the new standard, and are a better reflection of the ozone 
pollution problem that each area faces than the interim emissions 
tests.
    One commenter who supported requiring the budget test asked EPA to 
clarify whether 1-hour budgets remain in effect after revocation of the 
1-hour standard. Once we revoke the standard, these budgets do not 
remain in effect for the 1-hour standard as conformity does not apply 
with respect to the 1-hour standard. However, those 1-hour budgets that 
are adequate or approved continue to be part of an area's SIP and

[[Page 40027]]

are therefore appropriate to use as proxies for the 8-hour standard. 
EPA notes that adjusting the 1-hour ozone budgets to correspond to the 
boundaries of the 8-hour area for purposes of conducting 8-hour ozone 
conformity analyses is legally appropriate since any 1-hour ozone SIP 
demonstrations and budgets would only be used as a proxy for the 8-hour 
ozone standard and would themselves no longer be for an applicable 
standard. Therefore, EPA believes that using the portion of the 1-hour 
SIP budget that covers the 8-hour nonattainment is appropriate for 8-
hour conformity and that the relevant portion can be derived through 
the consultation process. For example, adding county level emissions 
to, or subtracting county level emissions from, the 1-hour budgets to 
reflect the geographic 8-hour area does not need to occur through a SIP 
revision or be reviewed through EPA's adequacy process. Using portions 
of 1-hour SIP budgets in this manner does not necessitate 8-hour or 1-
hour SIP revisions, but merely are administrative analyses of what 
tests should be conducted for conformity purposes prior to submission 
of 8-hour SIPs. How these budgets are derived can be determined through 
the consultation process and documented in an area's conformity 
determination.
    Many commenters supported our proposal to offer a menu of choices 
and use the interagency consultation process to choose the test. Most 
of these commenters simply stated their preference, but a few offered 
that the 2002 baseline year test may be better than the budget test 
when the 1-hour budgets are based on outdated planning assumptions or 
models. Today's final rule preserves an area's ability to decide that 
the 1-hour budgets are not the most appropriate test. However, budgets 
cannot be ignored solely because more recent planning assumptions or 
models are available. When budgets are not currently in use and in 
other cases where it is more appropriate for meeting Clean Air Act 
section 176(c) requirements, the consultation process must be used and 
the rationale for using other test(s) documented in the conformity 
determination.
    Another commenter suggested that EPA should allow areas to choose 
among several tests because it has not yet classified areas or 
established attainment years. This was true as of the November 5, 2003 
proposal, but at this point EPA has classified areas and established 
attainment years in the final 8-hour designations rule (April 30, 2004, 
69 FR 23858). A few commenters thought that emissions should be held as 
low as possible, and therefore EPA should require areas to determine 
which of the tests is more protective through the interagency 
consultation process. Another commenter thought that the state air 
quality agency alone should choose the test to ensure that the 
conformity requirements of the Clean Air Act are met. EPA believes, 
however, that the budget test using the 1-hour budgets generally 
maintains current air quality progress and satisfies the Clean Air Act 
requirement that transportation activities not cause new violations, 
worsen existing violations, or delay timely attainment, as described 
above. Therefore, EPA is not incorporating the commenter's suggestion 
in today's rule, although air quality agencies are expected to play a 
significant role in the selection of the appropriate test through the 
consultation process in these areas, because they developed 1-hour SIPs 
and budgets.
    One commenter suggested that where the 8-hour area is smaller than 
the 1-hour area (Scenario 2), a budget could be created for the 8-hour 
area by reducing the 1-hour budget proportional to the population of 
the 8-hour area (i.e., 8-hour budget = 1-hour budget x 8-hour area 
population / 1-hour area population). EPA does not agree that this 
method would necessarily produce an appropriate proxy budget, because 
such a calculation may not accurately reflect the portion of the 1-hour 
SIP budget that applies for the geographic area covered by the 8-hour 
standard. Furthermore, emissions are not directly proportional to 
population but also depend on travel distances, speeds, and fleet 
characteristics, all of which may differ greatly among counties within 
one nonattainment area.
    Where the 8-hour area is larger than the 1-hour area (Scenario 3), 
one commenter suggested that EPA should allow conformity to be 
demonstrated if the entire 8-hour area can meet the 1-hour budget. EPA 
did not propose this option in the November 2003 proposal because we do 
not believe that it would be possible for a larger 8-hour area to meet 
a 1-hour budget for a smaller area. However, EPA believes that if this 
case does occur in practice, such an area could demonstrate conformity 
for the 8-hour standard by completing the budget test with the 1-hour 
budget for the entire 8-hour nonattainment area. Although this case is 
not explicitly addressed in the regulatory text for today's final rule, 
if an 8-hour area that is larger than the 1-hour area meets its 1-hour 
SIP budgets, it would satisfy the requirements of Sec.  
93.109(e)(2)(iii). It would meet the budget test in (A) of this 
paragraph, and it would implicitly show that the interim emissions 
test(s) in (B) of this paragraph had been met.
    Several commenters requested clarification that all of the test 
options remain available in subsequent conformity determinations until 
adequate or approved budgets for the 8-hour standard are in place. 
Though today's final rule does not offer the full range of options 
proposed, areas will still evaluate how to apply the budget test using 
1-hour SIP budgets with each new conformity determination. In addition, 
the consultation process will be used to decide details for how to 
apply the interim emissions tests where the 8-hour boundary is larger 
than or partially overlaps with the 1-hour boundary (Scenario 4). Until 
8-hour ozone budgets are available, areas do have the option to apply 
these tests as appropriate in any subsequent conformity determinations 
regardless of how the test was applied in a prior conformity 
determination.
    The final rule also gives flexibility for how the interim emissions 
tests are applied in Scenario 3 and 4 areas. EPA is finalizing the 
budget test plus interim emissions tests either for:
     The whole area to be covered by an 8-hour SIP,
     the portion not covered by the 1-hour budget, or
     the entire portion of the 8-hour ozone nonattainment area 
within an individual state, in the case where 1-hour SIP budgets are 
established for each state in a multi-state nonattainment area.

EPA originally proposed that these areas would meet the interim 
emissions tests for the whole area, or the budget test for the 1-hour 
portion plus the interim emissions tests for the remainder. Though we 
did not specifically propose that areas would use the budgets plus the 
interim emissions tests for the entire area, we did propose that areas 
could meet the interim emissions tests for the whole area. Today's 
final rule includes this option because EPA now believes that, in most 
cases, the budgets must be used, but that offering a choice where 
possible with regard to the interim tests provides some flexibility for 
areas where they are also required. This option is a logical outgrowth 
of the proposal and comments received regarding the use of budgets. In 
addition, because many commenters supported the use of interim 
reduction tests by themselves for the whole area, EPA believes there is 
support for this option in conjunction with the 1-hour SIP budgets 
prior to 8-hour SIPs being established. Finally, as described above, 
EPA is finalizing a third interim

[[Page 40028]]

emissions test option for multi-state nonattainment areas with separate 
1-hour SIP budgets, due to comments received from such areas.
    One commenter raised questions about the situation where an 
existing 1-hour ozone nonattainment or maintenance area can demonstrate 
conformity, but the new 8-hour counties within the same 8-hour 
nonattainment area cannot. In this general case, the commenter believed 
that the 1-hour portion of the 8-hour ozone nonattainment area should 
be able to proceed with projects that will be implemented in the 1-hour 
portion even though the new 8-hour portion of the area fails to 
demonstrate conformity.
    EPA does not agree. As described in Section III., during the one-
year conformity grace period, conformity using the appropriate 1-hour 
ozone conformity test applies only in 1-hour nonattainment and 
maintenance areas. Once the grace period for the 8-hour standard 
expires and the 1-hour standard is revoked, however, the 1-hour ozone 
standard and conformity requirements for that standard no longer apply. 
At that time, new 8-hour ozone nonattainment areas (including the 
previous 1-hour area or portions thereof) must demonstrate conformity 
for the entire 8-hour area or the area will lapse. Therefore, EPA has 
not changed the final rule to address this comment. However, EPA will 
elaborate how 8-hour conformity determinations in multi-jurisdictional 
areas with existing 1-hour SIP budgets in implementation guidance. 
Please see Section I.B.2. of today's final rule for more information 
about EPA's conformity website.
    Finally, some commenters supported the use of 1-hour SIP budgets 
based on legal rationale with which EPA disagrees. First, commenters 
stated that the Clean Air Act does not allow existing approved budgets 
for any pollutant or standard to be waived. Second, commenters stated 
that all elements of a SIP, including 1-hour budgets, remain 
enforceable until revisions are submitted by the state and approved by 
EPA as satisfying the requirements of Clean Air Act sections 110(k) and 
(l). EPA agrees that 1-hour ozone budgets should be used for 8-hour 
ozone conformity, but disagrees with these legal arguments. In section 
109(d)(1) of the Clean Air Act, Congress directed EPA to review the 
standards every 5 years and ``make such revisions in such criteria and 
standards and promulgate such new standards * * *.'' EPA interprets 
``make such revisions in * * * standards'' to mean that EPA has the 
authority to replace one standard with another, and that implicit in 
this authority is the authority to revoke a standard. Once a standard 
is revoked, although control measures remain in a SIP the budgets for 
that standard are no longer in force for conformity purposes because 
areas are not required to conduct conformity determinations for such 
standards. Therefore, EPA does not agree that the 1-hour ozone budgets 
would automatically still apply for 8-hour conformity purposes, nor 
that section 110(k) and (l) requirements would have to be met before 
areas stopped using these budgets for conformity purposes. Section 
176(c)(5) of the Act terminates conformity for the 1-hour standard at 
revocation. Conformity for the 8-hour standard begins one year after 
designation, but the SIP contains no budgets for the 8-hour standard 
until 8-hour SIPs are submitted. EPA believes that the remaining 1-hour 
budgets will generally represent the best approximation of future 8-
hour budgets and thus should be used for 8-hour conformity in most 
cases, but does not agree that they must always be used as a legal 
matter as suggested by the commenter.
    Third, commenters argued that EPA's previous statement in the 
preamble to the August 15, 1997 conformity rule supports their view 
that 1-hour SIP budgets in approved SIPs must be used for conformity 
determinations under the 8-hour standard. They quoted, ``EPA does not 
believe that it is legal to allow a submitted SIP to supersede an 
approved SIP for years addressed by the approved SIP * * *. Clean Air 
Act section 176(c) specifically requires conformity to be demonstrated 
to approved SIPs. SIP revisions that EPA has approved under Clean Air 
Act section 110 are enforceable and cannot be relieved by a submission, 
even if that submission utilizes better data.'' (62 FR 43783). EPA does 
not agree that this quote is relevant, as we are not discussing 
submitted budgets that will replace the approved 1-hour ozone budgets. 
This language must be interpreted in context as referring to SIP 
revisions for the same applicable standard as the existing SIP.
    Furthermore, EPA does not agree that Clean Air Act section 
176(c)(2)(A) requires the use of 1-hour ozone budgets for conformity 
under the 8-hour standard. This section requires that emissions from 
the planned transportation plan and TIP must be consistent with 
emissions in the applicable SIP, but a 1-hour ozone SIP ceases to be 
the applicable SIP once the 1-hour standard is revoked. The 8-hour SIP, 
once available, will be the applicable SIP for conformity 
determinations under the 8-hour ozone standard. Instead of relying on 
Clean Air Act section 176(c)(2)(A), EPA believes the 1-hour budgets 
must be used where possible in 8-hour areas because their use best 
meets the requirements of 176(c)(1)(A) and (B) for the 8-hour standard.

VII. Regional Conformity Tests in PM[bdi2].[bdi5] Areas

A. Description of Final Rule

    Today's final rule requires that the budget test be used to 
complete a regional emissions analysis once a PM2.5 SIP is 
submitted with budget(s) that EPA has found adequate or approved. 
Although the first PM2.5 SIP may be an attainment 
demonstration, PM2.5 nonattainment areas ``are free to 
establish, through the SIP process, a motor vehicle emissions budget 
[or budgets] that addresses the new NAAQS in advance of a complete SIP 
attainment demonstration. That is, a state could submit a motor vehicle 
emissions budget that does not demonstrate attainment but is consistent 
with projections and commitments to control measures and achieves some 
progress towards attainment.'' (August 15, 1997, 62 FR 43799). To be 
approvable, such a SIP would include inventories for all emissions 
sources and meet other SIP requirements. EPA encourages nonattainment 
areas to develop their PM2.5 SIPs in consultation with 
federal, state, and local air quality and transportation agencies as 
appropriate.
    Today's final rule also requires that PM2.5 
nonattainment areas meet one of the following interim emissions tests 
for conformity determinations conducted before adequate or approved 
PM2.5 SIP budgets are established:
     The build-no-greater-than-no-build test, or
     the no-greater-than-2002 emissions test.

    The rule allows PM2.5 nonattainment areas to choose 
between the two interim emissions tests each time that they determine 
conformity during this period. For example, an area may use the build-
no-greater-than-no-build test in its first conformity determination for 
the PM2.5 standard and then use the no-greater-than-2002 
emissions test in a subsequent conformity determination. However, under 
this final rule, the same test must be used for each analysis year in a 
given conformity determination. In other words, an MPO may not use the 
build-no-greater-than-no-build test in one analysis year and the no-
greater-than-2002 test in another analysis year for the same conformity 
determination. As noted in Section V. with respect to certain ozone 
areas, to do otherwise

[[Page 40029]]

would be unnecessarily complicated and would imply that one test used 
consistently for all years might not demonstrate conformity. The 
interagency consultation process should be used to determine which test 
is appropriate. EPA concludes that for reasons similar to those 
described for 8-hour ozone areas classified marginal and subpart 1 
areas, conformity is demonstrated if the projected transportation 
system emissions reflecting the proposed plan or TIP (build) are less 
than or equal to either the emissions from the existing transportation 
system (no-build) or the level of motor vehicle emissions in 2002.
    During the time period before a SIP is submitted and budgets are 
found adequate or approved, regional emissions analyses will be 
completed at a minimum for directly emitted PM2.5 from motor 
vehicle tailpipe, brake wear, and tire wear emissions, as described in 
Section VIII. This section also provides information on EPA's further 
consideration of PM2.5 precursors in conformity analyses. 
Sections IX. and X. describe situations under which regional emissions 
analyses would also include direct PM2.5 emissions from re-
entrained road dust and construction-related dust.
    The consultation process should be used to determine the models and 
planning assumptions for completing any regional emissions analysis 
consistent with related requirements, as required by Sec.  
93.105(c)(1)(i). See the regulatory text in Sec.  93.109(i) for a 
general overview of when the budget test and interim emissions tests 
apply in PM2.5 areas, and Sec.  93.119(e) for a description 
of the interim emissions tests for PM2.5 nonattainment 
areas.

B. Rationale and Response to Comments

    The final rule addresses the concerns of many stakeholders by 
providing flexibility before adequate or approved PM2.5 SIP 
budgets are established. EPA received a number of comments on this 
section of the proposal. Most of the commenters supported the proposal 
to allow areas to choose between the two interim emissions tests. These 
commenters indicated that having a choice provided appropriate 
flexibility for local areas to tailor conformity requirements. One 
commenter stated that the interagency consultation process should be 
used to select the interim emissions test to be used in the 
nonattainment area.
    EPA agrees with these commenters. As described in the proposal, EPA 
has previously determined that only ozone and CO areas of higher 
classifications are required to satisfy both statutory requirements 
that transportation activities not cause or contribute to violations of 
the standards or delay attainment (Clean Air Act section 176(c)(1)(B)) 
and that such activities contribute to annual emissions reductions 
(Clean Air Act section 176(c)(3)(A)(iii)) (January 11, 1993 proposed 
rule, 58 FR 3782-3783). EPA continues to believe that Clean Air Act 
section 176(c)(3)(A)(iii) does not apply to any other areas, including 
PM2.5 areas; only Clean Air Act section 176(c)(1)(B) applies 
to these areas. To that end, the conformity rule currently allows many 
areas to conform based on only one interim emissions test if 
transportation emissions are consistent with current air quality 
expectations, rather than having to complete two tests and contribute 
further reductions toward attainment. Today's final rule continues to 
apply this same test structure and rationale to PM2.5 areas. 
EPA also agrees that an area's interagency consultation process 
provides an appropriate forum for determining which of the two interim 
emissions tests should be used in conformity determinations.
    Some commenters recommended that PM2.5 nonattainment 
areas be required to pass both interim emissions tests prior to SIP 
budgets being found adequate or approved, for a variety of reasons. 
These commenters noted that it is possible that an area could pass the 
no-greater-than-2002 test, but fail the build-no-greater-than-no-build 
test. According to the commenter, failing the build-no-greater-than-no-
build test could indicate increasing emissions and be inconsistent with 
Clean Air Act section 176(c)(1) because any increased emissions could 
cause or contribute to new violations, worsen existing violations or 
delay timely attainment of the air quality standard. In addition, two 
other commenters recommended that EPA require both interim emissions 
tests in areas with the more serious PM2.5 nonattainment 
problems because these areas should be required to meet more stringent 
conformity tests. Three additional commenters indicated that both 
interim emissions tests should be required because this is the most 
conservative approach to ensure protection of public health, that it 
would reduce transport of emissions and it would maintain progress 
toward meeting the standard. One of these commenters indicated that the 
build-no-greater-than-no-build test requires that total emissions be 
less than a no-build scenario and the no-greater-than-2002 test 
prevents increases above a historical level of emissions; therefore, 
both tests should be applied.
    EPA disagrees with the assertion that in order to demonstrate 
conformity during the time period before PM2.5 budgets are 
found adequate or are approved an area must pass both interim emissions 
tests. As described above, EPA has previously determined that only 
ozone and CO areas of higher classifications are required to satisfy 
both statutory requirements that transportation activities not cause or 
contribute to violations of the standards or delay attainment (Clean 
Air Act section 176(c)(1)(B)) and that such activities contribute to 
annual emissions reductions (Clean Air Act section 176(c)(3)(A)(iii)) 
(January 11, 1993 proposed rule, 58 FR 3782-3783). EPA continues to 
believe that either of the two interim emissions tests are sufficient 
to meet Clean Air Act section 176(c)(1)(B) provisions. As noted by 
these commenters an area could pass only the build-no-greater-than-no-
build test and fail the no-greater-than-2002 test and this would 
allegedly indicate increasing emissions which could cause new 
violations, worsen existing violations or delay timely attainment of 
the standard. EPA recognizes that meeting only the build-no-greater-
than-no-build test is a possible outcome in some areas; however, as EPA 
stated in the section of the preamble to the November 24, 1993 final 
transportation conformity rule that addressed requirements for 
NO2 and PM10 areas during the time before a SIP 
was submitted, ``The build/no-build test is consistent with the interim 
requirements for ozone and CO areas and sufficient to ensure that the 
transportation plan, TIP or project is not itself causing a new 
violation or exacerbating an existing one.'' (58 FR 62197)
    Conversely, some areas may fail the build-no-greater-than-no-build 
test and pass only a no-greater-than-2002 test. EPA believes that this 
would also be an acceptable outcome because it would ensure that 
emissions from on-road mobile sources are no greater than they were 
during the 2002 baseline year that is used for SIP planning purposes 
under the new standards. If future on-road emissions do not increase 
above their base year levels, EPA believes that new violations will not 
be created, existing violations will not be made worse and timely 
attainment will not be delayed. This is consistent with the approach 
applied to emissions in PM10 and NO2 areas in the 
preamble to the January 11, 1993 notice of proposed rulemaking for the 
transportation conformity rule. Specifically, in that preamble EPA

[[Page 40030]]

stated that, ``* * * EPA believes that preventing emissions from 
increasing above 1990 levels would be sufficient to prevent the 
exacerbation of existing violations during the interim period.'' (58 FR 
3783).
    With regard to the recommendations that we require both interim 
emissions tests based either on the severity of an area's nonattainment 
problem or on the conservative nature of requiring both tests, EPA is 
not accepting either recommendation. As stated above, EPA continues to 
believe that either test is sufficient to meet the requirements of 
Clean Air Act section 176(c)(1)(B) which applies to PM2.5 
nonattainment areas. Additionally, EPA intends to designate all 
PM2.5 nonattainment areas under subpart 1 of the Clean Air 
Act. Subpart 1 does not mandate a classification scheme for 
nonattainment areas based on the severity of an area's air quality 
problem. Therefore, there is no basis for EPA to determine in this 
rulemaking what would constitute a serious PM2.5 
nonattainment problem and require both interim emissions tests in such 
areas. Areas should use the interagency consultation process to 
determine which of the two tests is most appropriate in their area. 
Although areas may voluntarily choose to perform both interim emissions 
tests during the time before a SIP is submitted and budgets are found 
adequate or approved if a conservative approach is desired, they are 
not required to do so. EPA believes that areas should make their own 
decisions on how conservative to be prior to SIP adoption so long as 
they meet the minimum requirements for conformity.
    One commenter recommended that only the build-no-greater-than-no-
build test be made available to PM2.5 areas because it shows 
improvements resulting from the transportation plan and TIP. This 
commenter was concerned that the no-greater-than-2002 emissions test is 
not appropriate in PM2.5 areas because re-entrained road 
dust is dependent on VMT and future year emissions will always be 
greater than 2002 emissions when dust emissions increases are included. 
EPA has not changed the rule in response to this comment.
    First, because EPA believes that some PM2.5 areas may be 
able to use the no-greater-than-2002 test successfully, EPA does not 
want to require that all areas must use the build-no-greater-than-no-
build test. EPA believes that areas should have a choice of the two 
interim emissions tests since EPA concludes that both tests allow areas 
to demonstrate that they meet the requirements of Clean Air Act Section 
176(c)(1)(B).
    Second, while some PM10 areas experienced difficulties 
passing the baseline year test, it is not certain that PM2.5 
areas will experience the same difficulty. Road dust represents a much 
smaller fraction of total PM2.5 mass than of PM10 
because most road dust particles are larger than 2.5 microns. Also, as 
stated in Section IX. of today's notice, EPA is finalizing a provision 
that only requires re-entrained road dust to be included in conformity 
determinations before PM2.5 SIP budgets are available if EPA 
or the state air agency makes a finding that road dust is a significant 
contributor to an area's PM2.5 nonattainment problem. 
Therefore, not all areas will be required to include road dust in 
conformity determinations initially. For areas where it is determined 
that road dust is a significant contributor to the nonattainment 
problem and therefore must be included in conformity determinations, 
EPA will be issuing future guidance on how to quantify more 
appropriately road dust emissions for purposes of conducting regional 
emissions analyses.
    Another commenter suggested that neither of the interim emissions 
tests should be required before a SIP is submitted and that mobile 
sources should not be targeted when they may not be the source of an 
area's PM2.5 problem. EPA disagrees. Clean Air Act section 
176(c)(6) requires that conformity apply in new nonattainment areas one 
year after the effective date of the nonattainment designation, even 
prior to the submission of SIPs establishing budgets for a particular 
pollutant. Clean Air Act section 176(c)(4) provides EPA with the 
authority to establish conformity tests that will ensure that 
transportation plans, programs and projects do not result in new 
violations of an air quality standard, worsen an existing violation or 
delay timely attainment of a standard during that time period. While 
the contribution of mobile sources to PM2.5 nonattainment problems is 
likely to vary from area to area, on-road sources are likely to make 
some contribution in all areas. Therefore, EPA believes that in order 
to protect public health it is both required by the Clean Air Act and 
necessary for PM2.5 areas to begin demonstrating conformity using 
appropriate interim emissions tests once conformity applies, before 
adequate or approved SIP budgets are established.
    One commenter expressed support for the use of the budget test 
particularly in maintenance areas. The commenter noted that the budget 
test provides the area with a high degree of confidence that it will 
remain in attainment if emissions are held to the SIP budget levels. 
EPA agrees that once a SIP is submitted and budgets are found adequate 
or approved, the budget test is appropriate for meeting statutory 
requirements. Section 176(c)(2)(A) requires, in part, that a 
transportation plan or TIP may only be found to conform if a final 
determination has been made that emissions expected from the 
implementation of the plan and TIP are consistent with estimates of 
emissions from motor vehicles and necessary emissions reductions 
contained in the applicable implementation plan.
    A number of comments were received on the suggestion that areas 
could submit early SIP budgets. One commenter supported this 
suggestion, while several other commenters were opposed to the 
suggestion. These commenters opposing early budgets believed that: 
Budgets should be developed as part of an area's attainment 
demonstration with adequate interagency consultation recognizing the 
complexities of the PM2.5 problem; early budgets could 
isolate motor vehicle emissions in advance of considering reductions 
from other source categories; and the idea of developing these budgets 
in advance of the attainment demonstration is flawed in principle and 
would encourage incomplete air quality planning and delay the overall 
SIP development process.
    EPA believes that commenters misunderstood the proposal, and we 
continue to believe that it is acceptable for areas to establish early 
motor vehicle emission budgets through the SIP process at an area's 
discretion. If an area chooses to prepare an early SIP, it must develop 
that SIP in consultation with EPA and state, local and federal 
transportation and air quality planners. To be approvable, such a SIP 
would have to include inventories for all source sectors and meet other 
SIP requirements. While these early SIPs would have to show some 
progress toward attainment, it is not a requirement that all of the 
reductions would come from on-road motor vehicles. It is not EPA's 
intention that motor vehicle emissions be solely controlled in a 
voluntary early SIP, but rather, to highlight that some areas may find 
it beneficial to establish early budgets by selecting appropriate 
controls on a range of sources instead of relying on one of the interim 
emissions tests to demonstrate conformity for PM2.5. EPA 
agrees that PM2.5 nonattainment is a complex issue. However, 
some areas will have

[[Page 40031]]

information (e.g., air quality studies, modeling results) to guide them 
in the development of an early SIP, if desired.
    Furthermore, EPA does not agree that the idea of early SIPs is 
flawed or that it will result in incomplete air quality planning or 
delay required SIPs. A voluntary early SIP does not relieve an area of 
its obligation ultimately to submit other required SIPs in a timely 
manner (e.g., an attainment demonstration); therefore, an early SIP 
should not lead to incomplete air quality planning in the long run. An 
area that decides to submit an early SIP should recognize that it must 
still comply with submission dates for other applicable SIP 
requirements.
    One commenter stated that early PM2.5 SIPs may include 
some quantification of direct PM2.5 emissions, but that 
these preliminary quantifications in emission inventories, which are 
not explicitly intended to be SIP budgets, should not trigger 
additional conformity requirements. EPA does not anticipate such early 
SIP submissions to cause confusion in the conformity process, as 
suggested by this commenter.
    EPA believes that only control strategy SIPs establish motor 
vehicle emission budgets for conformity purposes. Section 93.101 of the 
conformity rule defines a control strategy SIP as an implementation 
plan which contains specific strategies for controlling the emissions 
of and reducing ambient levels of pollutants in order to satisfy Clean 
Air Act requirements for demonstrations of reasonable further progress 
and attainment. If the early SIP described by the commenter is 
submitted to satisfy different Clean Air Act requirements, it would 
most likely not establish budgets or trigger additional conformity 
requirements. It should be noted that Sec.  93.105(b)(2) of the 
conformity rule requires that the interagency consultation process be 
used during the development of an area's SIP. Therefore, the MPO should 
be aware of any SIPs that are to be submitted that will establish 
budgets for future conformity determinations.

C. Comments Not Related to the Proposal

    One commenter offered suggestions for alternate interim emissions 
tests for PM2.5 areas. The commenter believed that 
PM2.5 nonattainment areas will need reductions from on-road 
sources even before a SIP is established in order to attain the air 
quality standard. The commenter argued that EPA has the authority to 
require reductions in all nonattainment areas before a SIP is submitted 
under Clean Air Act Section 176(c)(1)(A), which requires conformity to 
the purpose of the SIP.
    The commenter described an alternate interim emissions test that 
should be used prior to a SIP being submitted and budgets being found 
adequate or approved. Specifically, the transportation agency would 
prepare a motor vehicle emissions trends analysis for the 20-year 
planning horizon based on the current transportation plan. The 
transportation agencies would then assess the emissions reductions that 
could be achieved by the implementation of facilities, services and 
economic incentives. Based on this assessment the area would select 
measures to optimize the emissions reductions from the transportation 
sector towards attainment. The consultation process would be used to 
establish an emissions reduction curve that would serve as a conformity 
benchmark until a SIP is developed and submitted to EPA. The commenter 
believes such a test would identify the range of emissions reductions 
available from the transportation sector, yield valuable information 
for the development of a SIP and establish a framework for interagency 
collaboration to identify emissions reductions that could be 
implemented before adoption of a SIP containing motor vehicle emission 
budgets.
    EPA is not changing the final rule in response to this comment. EPA 
agrees that the process described by the commenter may yield valuable 
information for the development of the PM2.5 SIP for an 
area, and areas could elect to use it at their discretion for that 
purpose. However, EPA continues to believe that only Clean Air Act 
section 176(c)(1)(B) applies to PM2.5 nonattainment areas 
prior to the time that a SIP is submitted and budgets are found 
adequate or approved, since section 176(c)(2)(A) requiring compliance 
with budgets only applies once a SIP is established. Although section 
176(c)(1)(A) does require conformity to the purposes of a SIP, where a 
SIP has not been submitted to establish budgets, EPA does not believe 
this provision would mandate a test such as that suggested by the 
commenter.
    As discussed above, EPA has concluded that use of either existing 
interim emissions test is sufficient to meet the requirements of 
section 176(c)(1)(B) in PM2.5 areas. Moreover, the SIP 
process, which includes consultation with transportation agencies, is 
the appropriate venue for deciding on SIP control strategies for 
attaining the PM2.5 air quality standard. Requiring a test 
such as the one described by the commenter would in effect extend the 
provisions of Clean Air Act section 176(c)(3)(A)(iii) requiring 
emissions reductions to PM2.5 nonattainment areas as a 
mandatory matter, which is inconsistent with the statute.
    The same commenter also recommended a change to the build-no-
greater-than-no-build test for PM2.5 areas. Specifically, 
the commenter recommended that emissions from the build scenario be 
compared to both the no-build scenario as is currently required and 
also to emissions resulting from implementing the projects in the 
current fiscally constrained transportation plan. The commenter 
believes that it is reasonable to expect that projects in the current 
plan would be implemented because of past political decisions, resource 
commitments and existing emissions analyses. Therefore, the commenter 
believes that area should examine the consequences of changing the 
current transportation plan.
    EPA does not agree with requiring this type of test in 
PM2.5 nonattainment areas. EPA believes that the current 
build/no-build test alone, as used for other pollutants and standards, 
is sufficient and more appropriate for meeting Clean Air Act section 
176(c)(1)(B) requirements, which are intended to ensure that the 
emissions produced by an area's existing and planned transportation 
system are consistent with air quality goals. In contrast, the 
commenter's suggestion for redefining the build and no-build scenarios 
would focus conformity determinations on the specific projects and 
ongoing transportation decisions that are reflected within plans and 
TIPs. EPA believes that the transportation planning process is the more 
appropriate forum for deciding which specific projects are necessary to 
meet an area's transportation needs. As long as the statutory 
conformity requirements are met through the current form of the build/
no-build test, EPA believes that additional tests such as the commenter 
suggested are not necessary to ensure that Clean Air Act requirements 
are met. Therefore, EPA is not including this suggested test in today's 
final rule.

VIII. Consideration of Direct PM2.5 and PM2.5 
Precursors in Regional Emissions Analyses

A. Description of Final Rule

    Today's final rule requires that all regional emissions analyses in 
PM2.5 nonattainment and maintenance areas consider directly 
emitted PM2.5 motor

[[Page 40032]]

vehicle emissions from the tailpipe, brake wear, and tire wear. The 
regulatory text can be found in Sec.  93.102(b)(1). Sections IX. and X. 
provide information on when re-entrained road dust and construction-
related dust must also be included in PM2.5 conformity 
analyses.
    To calculate emissions factors for direct PM2.5 from 
motor vehicles all states except California would use the latest EPA-
approved motor vehicle emissions factor model (currently MOBILE6.2). 
PM2.5 nonattainment and maintenance areas in California 
would use EMFAC2002 or a more recently EPA-approved model. MOBILE6.2 
and California's EMFAC2002 are designed to generate emissions factors 
for direct PM2.5 as well as other emissions from on-road 
vehicles in the same modeling run.
    EPA is not finalizing any requirements for addressing 
PM2.5 precursors in transportation conformity determinations 
at this time. EPA will be proposing a broader PM2.5 
implementation rule to seek comment on options for addressing 
PM2.5 precursors in the New Source Review program and in SIP 
planning activities such as reasonable further progress plans, 
attainment demonstrations, reasonably available control technology 
(RACT) requirements, and reasonably available control measure (RACM) 
analyses. EPA believes that it would be inappropriate to select an 
option for addressing PM2.5 precursors in transportation 
conformity determinations prior to considering the precursor options in 
the PM2.5 implementation rule. EPA plans to promulgate 
conformity requirements that address precursors prior to 
PM2.5 designations being effective.
    In the November 5, 2003 proposal, EPA presented several conformity 
options for PM2.5 precursors for comment. Specifically, EPA 
proposed to add potential transportation-related PM2.5 
precursors--NOX, VOCs, sulfur oxides (SOX), and 
ammonia (NH3)--for consideration in the conformity process. 
Under the proposal, a regional emissions analysis would be required for 
a given precursor if the PM2.5 SIP established an adequate 
or approved budget for that particular precursor.
    EPA also proposed two options for addressing how the various 
PM2.5 precursors would be considered in conformity 
determinations conducted before adequate or approved PM2.5 
SIP budgets are established. EPA proposed regulatory text in Sec. Sec.  
93.102(b)(2) and 93.119(f) for both of these options.
    The first proposed option would require regional emissions analyses 
for NOX and VOC precursors in all areas, unless the EPA 
Regional Administrator or the state air agency makes a finding that one 
or both of these specific precursors are not a significant contributor 
to the PM2.5 air quality problem in a given area. Regional 
emissions analyses would not be required for SOx and 
NH3 before an adequate or approved SIP budget for such 
precursors is established, unless EPA or the state makes a finding that 
on-road emissions of one or both of these precursors is a significant 
contributor.
    EPA's second option would only require regional emissions analyses 
for one or more PM2.5 precursors (i.e., NOX, VOC, 
SOX and NH3) before adequate or approved 
PM2.5 SIPs have been established if EPA or the state makes a 
finding that one or more of these precursors are significant 
contributors to the PM2.5 air quality problem in a given 
area.
    As stated above, EPA intends to finalize the transportation 
conformity rule's PM2.5 precursor requirements after further 
consideration through the PM2.5 implementation rule and 
before PM2.5 designations become effective. By finalizing 
the PM2.5 precursor requirements before the effective date 
of the designations, areas will be fully aware of the conformity 
requirements at the start of the one-year PM2.5 conformity 
grace period.
    Although today's final rule does not address PM2.5 
precursors, conformity implementers can begin preparing for 
PM2.5 conformity now, because this final rule includes the 
PM2.5 regional conformity tests that apply for 
transportation plan and TIP conformity determinations that occur before 
and after PM2.5 SIPs are established. In addition, the final 
rule and the existing conformity rule provide all other requirements 
for PM2.5 determinations. For example, an MPO might choose 
to begin the no-greater-than-2002 test, as described in Section VII., 
prior to the release of final PM2.5 precursor conformity 
requirements. Transportation and emissions modeling for 
PM2.5 areas could also be prepared based on today's final 
rule, if desired. This is because VMT and speed estimates are based on 
the existing conformity rule's requirements, and can be made without 
regard to which precursors apply. Furthermore, MOBILE6.2 and EMFAC2002 
emissions factor models generate direct PM2.5 and precursor 
emissions factors from on-road vehicles at the same time in the same 
modeling run. Once PM2.5 precursor requirements are 
finalized, PM2.5 areas can document in conformity 
determinations that the applicable interim emissions test is met for 
direct PM2.5 and any relevant precursors that apply.
    Finally, EPA is not re-opening the comment period on the proposed 
transportation conformity requirements for addressing PM2.5 
precursors in transportation conformity determinations. EPA will 
address all of the comments received on the November 2003 proposal's 
PM2.5 precursor options when we finalize these requirements, 
as described above.

B. Rationale and Response to Comments

    EPA received a number of comments on this portion of the proposal. 
Most commenters supported the requirement that direct PM2.5 
emissions from the tailpipe and brake and tire wear be addressed in all 
regional emissions analyses. EPA believes that it is important to 
address direct PM2.5 in conformity determinations because it 
is an important contributor to the air quality problem in these 
nonattainment areas and because of public health concerns with 
exposures to fine particles. A few commenters indicated that these 
direct emissions should only be required to be included in regional 
emissions analyses before a SIP is submitted if a finding of 
significance is made. One of these commenters also submitted the 
results of an emissions analysis that he prepared. The results of the 
analysis showed direct PM2.5 emissions from on-road mobile 
sources (including re-entrained road dust) compared to emissions of 
PM2.5 precursors and, in particular, emissions of 
NOX. One commenter indicated that her agency would have data 
available to make findings of significance. EPA believes that it would 
be inappropriate to require a significance finding before direct 
emissions from motor vehicles can be included in regional emissions 
analyses, prior to the submission of a SIP for an area.
    EPA believes that areas must include direct PM2.5 
emissions, including tailpipe emissions and emissions from brake and 
tire wear, in conformity determinations prior to the time that SIPs are 
submitted and budgets are found adequate. Clean Air Act Section 
176(c)(1)(B) requires that activities not cause or contribute to any 
new violation of the air quality standard, increase the frequency or 
severity of any existing violation of the standard or delay timely 
attainment or any required interim emission reductions or other 
milestones. In order for an area to demonstrate compliance with the 
requirements of Clean Air Act Section 176(c)(1)(B) before a SIP is 
established, the area

[[Page 40033]]

must, at a minimum, conduct a regional emissions analysis for direct 
PM2.5 emissions from motor vehicles. EPA anticipates that in 
most nonattainment and maintenance areas direct PM2.5 
emissions will be an important contributor to the PM2.5 air 
quality problem. For these reasons, EPA is requiring that 
transportation conformity determinations consider direct 
PM2.5 emissions. As noted above, EPA will finalize rules on 
how to account for PM2.5 precursors, after further 
consideration in the context of EPA's broader PM2.5 
implementation strategy. See Section IX. of this notice for more 
information on PM2.5 requirements for re-entrained road 
dust.
    One commenter indicated that EPA's insignificance policy should 
apply to PM2.5 emissions. EPA agrees with this commenter. 
The insignificance policy may be applied to direct PM2.5 
emissions during the period after a SIP is submitted for the area. If 
the SIP for the area demonstrates that direct PM2.5 
emissions from on-road mobile sources, including dust where relevant, 
do not need to be constrained in order to ensure expeditious attainment 
of the PM2.5 standard, the requirement for a regional 
emissions analysis for direct PM2.5 would no longer apply. 
See Section XXIII. for more details on requirements for demonstrating 
that motor vehicle emissions are insignificant contributors to an 
area's air quality problem.
    One commenter recommended that conformity tests for direct 
PM2.5 be done collectively, meaning that one budget test or 
interim emissions test be done for all of the relevant types of direct 
PM2.5. EPA agrees with the commenter. EPA expects all 
PM2.5 nonattainment and maintenance areas to complete the 
required regional emissions analyses for direct PM2.5 by 
examining all of the relevant types of direct PM2.5 in one 
analysis rather than separate analyses for each type of particle: 
Therefore, the analysis for direct PM2.5 must include:
     Tailpipe exhaust particles,
     Brake and tire wear particles,
     Re-entrained road dust, if before a SIP is submitted EPA 
or the state air agency has made a finding of significance or if the 
applicable or submitted SIP includes re-entrained road dust in the 
approved or adequate budget, and
     Fugitive dust from transportation-related construction 
activities, if the SIP has identified construction emissions as a 
significant contributor to the PM2.5 problem.

See Sections IX. and X. for more information on requirements for re-
entrained road dust and fugitive dust from construction activities.
    Three commenters expressed concern over the need to use MOBILE6.2 
to estimate PM2.5 motor vehicle emissions. One of the three 
was concerned about the accuracy of the modeling tools. Another was 
concerned about unexpected problems occurring because areas lack 
experience in using MOBILE to evaluate particulate matter levels.
    EPA understands the concerns that these areas have expressed. Since 
the conformity proposal was published in November 2003, EPA has 
released MOBILE6.2. MOBILE6.2 is based on the latest available 
information concerning vehicle emissions and is therefore the best 
available tool at this time for calculating on-road emissions of direct 
PM2.5 (e.g., tailpipe emissions and brake and tire wear). 
The Federal Register notice announcing the release of the model was 
published on May 19, 2004 (69 FR 28830). EPA released SIP and 
conformity policy guidance on the use of MOBILE6.2 on February 24, 
2004, entitled, ``Policy Guidance on the Use of MOBILE6.2 and the 
December 2003 AP-42 Method for Re-Entrained Road Dust for SIP 
Development and Transportation Conformity.'' EPA will also be releasing 
technical guidance on the use of the MOBILE6.2 model in the future. 
Information on training in the use of MOBILE6.2 and related policy 
memoranda are available on EPA's MOBILE Web site at http://www.epa.gov/otaq/m6.htm. EPA believes there is adequate time for new areas to gain 
MOBILE experience and conduct conformity analyses for the 
PM2.5 standard, before the end of the one-year conformity 
grace period for that standard.

IX. Re-entrained Road Dust in PM2.5 Regional Emissions 
Analyses

A. Description of Final Rule

    With today's action, EPA is finalizing the first of the two 
proposed options for addressing re-entrained road dust in conformity 
analyses prior to adequate or approved PM2.5 SIP budgets. 
During this time period, re-entrained road dust will only be included 
in regional emissions analyses if the EPA Regional Administrator or 
state air quality agency determines that re-entrained road dust is a 
significant contributor to the PM2.5 regional air quality 
problem. In other words, PM2.5 areas can presume that re-
entrained road dust is not a significant contributor and not include 
road dust in PM2.5 transportation conformity analyses prior 
to the SIP, unless EPA or the state finds road dust significant. Re-
entrained road dust is granular material released into the atmosphere 
as a result of motor vehicle activity on paved and unpaved roads.
    EPA is applying this approach regardless of whether a 
PM2.5 area is also a PM10 nonattainment or 
maintenance area. Therefore, even if the PM2.5 area is also 
a PM10 area, the state or MPO can presume that re-entrained 
road dust is not a significant contributor and exclude it from 
PM2.5 transportation conformity analyses prior to the SIP, 
unless EPA or the state finds road dust significant for 
PM2.5. Regulatory text for this rule change is in Sec. Sec.  
93.102(b)(3) and 93.119(f).
    An EPA or state air agency finding of significant re-entrained road 
dust emissions (a ``finding of significance'') would be based on a 
case-by-case review of the following factors: the contribution of road 
dust to current and future PM2.5 nonattainment; an area's 
current design value for the PM2.5 standard; whether control 
of road dust appears necessary to reach attainment; and whether 
increases in re-entrained dust emissions may interfere with attainment. 
Such a review would include consideration of local air quality data 
and/or air quality or emissions modeling results. Today's action with 
respect to PM2.5 road dust is consistent with EPA's existing 
insignificance policy for all areas as described in Section XIV.B.
    A finding of significance should be made only after discussions 
within the interagency consultation process for the PM2.5 
nonattainment area. These discussions should include a review of the 
data being considered. Interagency consultation will also ensure that 
all of the relevant agencies are aware that such a finding is being 
considered and is supported by the air quality information that is 
available. Findings of significance should be made through a letter to 
the relevant state and local air quality and transportation agencies, 
MPO(s), DOT, and EPA (in the case of a state air agency finding).
    Road dust SIP emissions inventories and regional emissions analyses 
for conformity would be calculated using methods described in EPA's 
guidance entitled, ``AP-42, Fifth Edition, Volume 1, Chapter 13, 
Miscellaneous Sources'' (US EPA Office of Air Quality Planning and 
Standards; available at http://www.epa.gov/ttn/chief/ap42/ch13/). 
States and MPOs should consult with EPA before using alternative 
approaches, and EPA approval is needed before such approaches can be 
used. Details on the use of AP-42 for road dust estimation are given in 
``Policy Guidance on the Use of MOBILE6.2 and the December 2003 AP-

[[Page 40034]]

42 Method for Re-Entrained Road Dust for SIP Development and 
Transportation Conformity,'' memorandum from Margo Oge and Steve Page 
to EPA Regional Air Division Directors, February 24, 2004 available at 
http://www.epa.gov/otaq/models/mobile6/mobil6.2_letter.pdf).
    EPA notes that the absence of a finding of significance prior to 
the SIP should not be viewed as the ultimate determination of the 
significance of road dust emissions in a given area. State and local 
agencies may find through the SIP development process that road dust 
emissions are significant and should be included in the 
PM2.5 SIP budget and subsequent conformity analyses, 
although they did not have sufficient data to support a finding prior 
to the development of the SIP.
    As described in the November 5, 2003 proposal, EPA plans to issue 
guidance on how to adjust estimated PM2.5 road dust 
emissions to reflect the true impact of re-entrained road dust on 
regional air quality. This guidance will take into account differences 
between road dust emissions measured near the roadway and measured on 
regional air quality monitors and allow states and MPOs to adjust road 
dust emissions estimates to reflect accurately the regional impact of 
these emissions. EPA plans to issue this guidance by the time final 
PM2.5 designations are effective.

B. Rationale and Response to Comments

    All of the commenters that directly addressed this issue supported 
the option of not requiring that re-entrained road dust be included in 
PM2.5 conformity analyses prior to an adequate or approved 
SIP budget, regardless of whether the area is also a PM10 
area. Reasons commenters stated for supporting this option included 
uncertainties about the role of re-entrained road dust for 
PM2.5 air quality, likelihood that re-entrained dust will be 
dominated by larger particles, and concerns about needless expenditure 
of resources. As discussed in the proposal, at issue is the question of 
whether or not re-entrained road dust has a significant impact on 
PM2.5 air quality and should be included in conformity 
analyses in all PM2.5 areas. EPA believes that, unless there 
is already strong evidence of the importance of re-entrained road dust 
for PM2.5 air quality, the proper time to make that 
determination is during the development of the PM2.5 SIP.
    There is still a great deal of uncertainty about the overall impact 
of re-entrained road dust on PM2.5, and evidence suggests 
that re-entrained road dust is likely to have a relatively small impact 
on PM2.5 compared to PM10 in general. The 
development of a SIP requires an in-depth review of all the available 
emissions and air quality data for a particular area. EPA expects that 
this review will resolve many of the uncertainties about the impact of 
re-entrained road dust on PM2.5 in an area. However, if 
clear evidence of the impact of re-entrained road dust in a local area 
is available before the SIP is developed, the option of finding road 
dust significant so that it is included in conformity analyses can 
provide for the protection of public health and the environment in the 
short term. In the absence of such a finding prior to a 
PM2.5 SIP, it is more productive for areas to focus control 
efforts on vehicle emissions that clearly contribute to the 
PM2.5 air quality problem, rather than on re-entrained road 
dust emissions that have not been found to be significant. In addition, 
EPA does not believe there is compelling evidence to require that 
PM10 areas presume that re-entrained road dust will be a 
significant contributor to PM2.5 air quality problems in all 
cases based on our current understanding and on the comments received.
    Several commenters suggested that the final rule require that both 
EPA and the state make findings of significance before road dust is 
included in conformity analyses. EPA is not making this change to the 
final rule because we believe it is unnecessary given that the finding 
will be discussed through the interagency consultation process. The 
language used in the final rule for PM2.5 road dust is 
consistent with how such findings for PM10 precursors have 
been implemented since the original 1993 conformity rule.
    One commenter who supported the option EPA is finalizing also 
suggested as an alternative that re-entrained road dust be counted as 
part of the area source inventory not subject to transportation 
conformity at all. EPA disagrees. While the deposition of silt on a 
roadway is not necessarily completely dependent on vehicle activity, 
the release of that silt into the atmosphere is dependent on vehicle 
activity, and is therefore properly classified as an on-road mobile 
source emission subject to transportation conformity requirements.
    Several commenters supported the future release of EPA guidance to 
allow road dust emissions estimates to be adjusted to reflect the true 
regional impact of those emissions. Several more commenters raised 
general concerns about the quality of methods available for estimating 
road dust emissions. These commenters believed that the existing 
methods overestimate road dust emissions. EPA agrees and believes that 
concerns about the inaccuracy of emission estimation methods arise from 
discrepancies between the observed emissions near the roadway surface 
and observed emissions at the regional air quality monitors. Allowing 
emissions estimates to be adjusted to reflect the true regional air 
quality impact through EPA's planned future guidance should alleviate 
many of these concerns. Without these adjustments, planners may not 
apply the proper combination of control measures on dust and vehicle 
emissions needed to address properly the regional PM2.5 air 
quality problem. Based on observed discrepancies, EPA believes that 
controls on road dust would have a smaller impact on regional air 
quality than would initially appear based on unadjusted emissions 
inventories, and the Agency's planned guidance will address this issue.
    Two commenters proposed that separate emission budgets be 
established for vehicle exhaust emissions and re-entrained road dust, 
rather than the current practice of including all on-road 
PM2.5 emissions in one regional emissions analysis. The 
commenters believe that this approach would ``avoid the risk that 
improvements in the measurement of a poorly characterized inventory be 
used to offset increases in direct emissions of primary particles from 
combustion.'' In general, EPA believes that emissions from all motor 
vehicle sources should be examined in a unified manner for 
transportation planning and air quality planning purposes. It is also 
important that conformity analyses in PM2.5 areas are 
consistent with how PM2.5 SIP budgets will be developed.
    As long as Clean Air Act requirements are met when all motor 
vehicle emissions are considered in conformity analyses, EPA does not 
believe it is beneficial to further constrain the transportation 
project or control strategy development processes of state and local 
governments for transportation conformity purposes. If it is determined 
that PM2.5 from road dust is significant, it may prove 
extremely difficult to meet a separate road dust budget with any growth 
in VMT. Because dust and vehicle PM2.5 both contribute to 
direct on-road PM2.5 emissions levels, EPA believes it would 
be appropriate to treat them jointly for purposes of transportation 
conformity. For these reasons, EPA is not requiring separate budgets 
for road dust and exhaust emissions.

[[Page 40035]]

X. Construction-Related Fugitive Dust in PM2.5 Regional Emissions 
Analyses

A. Description of Final Rule

    EPA is finalizing the proposal to include construction-related 
fugitive dust from highway or transit projects in regional emissions 
analyses in PM2.5 nonattainment and maintenance areas only 
if the SIP identifies construction dust as a significant contributor to 
the regional air quality problem. Construction-related fugitive dust is 
granular material released into the atmosphere during construction. 
Construction-related dust emissions would not be included in any 
PM2.5 conformity analyses before adequate or approved 
PM2.5 SIP budgets are established. Regulatory text is in 
Sec.  93.122(f) of this final rule. This is consistent with the way 
construction dust is considered in the current rule for PM10 
nonattainment and maintenance areas.
    The consultation process should be used during the development of 
PM2.5 SIPs when construction emissions are a significant 
contributor, so that these emissions are included in the SIP's motor 
vehicle emissions budget for conformity purposes. EPA has previously 
provided similar guidance to PM10 nonattainment and 
maintenance areas for PM10 construction-related emissions 
requirements.\13\ See the preamble to the proposal for this final rule 
for further information regarding how EPA intends to implement the 
PM2.5 construction dust requirement (November 5, 2003, 68 FR 
62711).
---------------------------------------------------------------------------

    \13\ October 28, 1996, memorandum entitled, ``Transportation 
Conformity: Regional Analysis of PM10 Emissions from 
Highway and Transit Project Construction,'' memorandum from Gay 
MacGregor, then-Director, Regional and State Programs Division, 
Office of Mobile Sources to EPA Regional Air Division Directors.
---------------------------------------------------------------------------

    Construction dust SIP emissions inventories and regional emissions 
analyses for conformity can be calculated using methods described in 
EPA's guidance entitled, ``AP-42, Fifth Edition, Volume 1, Chapter 13, 
Miscellaneous Sources'' (US EPA Office of Air Quality Planning and 
Standards; available at http://www.epa.gov/ttn/chief/ap42/ch13/) or 
locally developed estimation methods that are selected through the 
interagency consultation process.
    In addition, EPA will allow PM2.5 emissions to be 
adjusted to reflect the true impact of construction-related fugitive 
dust on regional air quality, as explained in Section IX. EPA will 
issue guidance on how to adjust estimated PM2.5 construction 
dust emissions to reflect more accurately the impact of construction 
dust on regional air quality before EPA's final PM2.5 
nonattainment designations are effective. Under EPA's future guidance, 
calculated emissions could then be adjusted downward, if appropriate 
and necessary, to account for discrepancies based on an analysis of the 
relative impact of construction dust on ambient PM2.5 
concentrations as determined by regional air quality monitors and the 
PM2.5 SIP's demonstration in a given area.

B. Rationale and Response to Comments

    Most of the commenters who addressed this issue supported the 
proposal that EPA is finalizing today. Section 176(c) of the Clean Air 
Act requires that the air quality impacts of transportation projects be 
evaluated so that new violations or worsened violations do not occur 
and that attainment is not delayed. If emissions of fugitive dust from 
highway or transit project construction contribute to air quality 
problems in PM2.5 areas and as a result, air quality is 
worsened or timely attainment is delayed, then it is appropriate to 
evaluate those emissions in conformity before federal funding or 
approval is given. Section 93.122(e) of the transportation conformity 
rule requires regional PM10 emissions analyses to include 
construction-related PM10 dust if the SIP identifies 
construction emissions as a contributor to the nonattainment problem.
    If construction-related fugitive PM10 is not identified 
as a contributor to the air quality problem in the SIP, areas are not 
required to include these emissions in the regional emissions analysis 
for transportation conformity. The consultation process should be used 
to help determine whether construction dust is a significant 
contributor to regional air quality problems in the development of the 
PM2.5 SIP, and EPA will consider the significance of 
construction dust in its review of the SIP submission. Today's action 
applies the current rule's general approach for PM10 areas 
to PM2.5 areas.
    One commenter who supported the proposal said that the 
determination of whether construction dust is a significant contributor 
to the air quality problem should consider the temporary nature of 
these emissions, the mitigating impact of construction dust suppression 
measures, and the limitations of existing fugitive dust estimation 
methods. EPA believes that it is appropriate to include construction 
dust mitigation measures required in the local area when determining 
the air quality significance of construction dust. The temporary nature 
of these emissions can only be considered if the release is so short in 
duration that it does not affect regional air quality. The limitations 
of the existing fugitive dust method described by the commenter will be 
addressed by allowing the adjustment of the dust emissions inventory to 
reflect the impact of dust on regional air quality, which will be 
discussed in future EPA guidance.
    A smaller group of commenters opposed any inclusion of construction 
dust in transportation conformity analyses, citing the temporary nature 
of these emissions. While EPA agrees that these emissions only occur 
during the construction phase of a transportation project and that they 
may also be covered by other requirements, this is not a compelling 
rationale for excluding them from transportation conformity if they do 
have a significant impact on regional air quality. Dust from highway or 
transit construction projects could contribute to regional air quality 
problems for months or even years depending on the size of the project. 
Therefore, EPA has not changed the final rule in response to this 
comment.
    Some commenters argued construction dust should not be included 
because it is already addressed in the nonroad or area source inventory 
and that different emissions models and control strategies apply to 
nonroad sources. Other commenters argued construction dust should not 
be included because VOC and NOX emissions from construction 
equipment used during road construction projects are not required to be 
included in conformity analyses. EPA disagrees, because these factors 
have no bearing on whether construction dust should be included in 
conformity determinations. Construction dust from highway or transit 
projects is the direct result of decisions made during the 
transportation planning process and these decisions should take those 
emissions into account. The fact that different estimation methods and 
control methods are used for these emissions does not negate the 
connection with the transportation planning process. If construction 
dust is determined to be a significant contributor to the regional air 
quality problem, the state or MPO should make sure that only 
construction dust from highway and transit projects and not from other 
types of construction projects is included in the conformity analysis.
    Several commenters argued construction dust should not be included 
because construction projects are separately covered by project-level 
and National Environmental Policy Act (NEPA) requirements. Because 
project-level and NEPA requirements do not

[[Page 40036]]

take into account other on-road sources of PM2.5 emissions 
in other portions of the nonattainment or maintenance area, relying on 
these requirements exclusively would miss situations in which 
additional construction dust emissions from transportation projects 
worsen an existing region-wide PM2.5 air quality problem.
    A few commenters asked that full interagency consultation be 
required as part of the SIP development process with respect to the 
issue of the significance of construction dust. EPA agrees. Section 
93.105(b)(1) of the conformity rule already requires that state and 
local transportation and air agencies, and other organizations with 
responsibilities for developing or implementing SIPs must consult with 
each other and with EPA, FHWA, and FTA field offices on the development 
of the SIP, transportation plan, TIP, and associated conformity 
determinations.
    One commenter stated that emission analyses to determine if 
construction dust is a significant contributor to regional air quality 
should be required only in PM2.5 areas for the 24-hour 
standard because the commenter believed that these emissions would have 
no effect on attainment of the annual PM2.5 standard. EPA 
disagrees since it is impossible to make the determination that 
construction dust emissions will have no effect on attainment of the 
annual PM2.5 standard in any area until a proper analysis 
has been done as part of the SIP development process, especially where 
construction activity continues for several years.
    One commenter suggested that Sec.  93.122(f)(2) should not include 
``the dust producing capacity of the proposed activities'' because the 
commenter believes this requirement exceeds the SIP inventory 
requirements. EPA believes that an estimation of the dust producing 
capacity of the proposed transportation project is necessary in order 
to make a determination of the significance of construction dust on 
regional air quality. It is clearly possible to do this since the 
language in Sec.  93.122(f)(2) is consistent with the requirement to 
account for construction dust for PM10 conformity, which has 
already been implemented for many years. Therefore, the final rule has 
not been changed in response to this comment.
    One commenter stated that construction dust emissions were 
generally more significant than emissions of re-entrained road dust. 
This commenter believed that without a regulatory requirement to 
account for construction-related PM2.5 emissions in all 
cases in conformity, effective measures to control these emissions 
would be inconsistent and only voluntary. As a result, this commenter 
recommended that construction dust emissions be considered in 
conformity analyses prior to the submission of an adequate 
PM2.5 SIP budget. EPA believes based on the available data 
that construction dust will not be significant in all areas and that 
therefore requiring the inclusion of construction dust before it has 
been determined to be significant through the SIP process is 
unnecessary and could lead to the diversion of limited state and local 
resources. Furthermore, EPA did not include an option for including 
construction dust in all cases in the November 2003 proposal. 
Therefore, EPA is not changing the rule in response to this comment.

XI. Compliance With PM2.5 SIP Control Measures

A. Description of Final Rule

    The final rule requires that FHWA and FTA projects in 
PM2.5 nonattainment and maintenance areas comply with the 
applicable SIP's PM2.5 control measures, when such measures 
exist. Under the final rule, FHWA and FTA would assure implementation 
of a required control or mitigation measure by obtaining enforceable 
written commitments from the project sponsor and/or operator prior to 
making a project-level conformity determination. This requirement would 
be satisfied if the project-level conformity determination contains a 
written commitment from the project sponsor to include the control 
measures in the final plans, specifications and estimates for the 
project. This final rule is consistent with a similar requirement for 
PM10 areas.
    EPA notes, however, that Sec.  93.117 is only applicable after a 
PM2.5 nonattainment area has an approved PM2.5 
SIP, because the requirement is to comply with the measures in the 
approved PM2.5 SIP. Today's final rule does not affect any 
separate state or other SIP requirements for compliance with control 
measures.
    The purpose of a PM2.5 control measure is to limit the 
amount of PM2.5 emissions from construction activities and/
or normal use and operation associated with the project. Examples of 
specific control or mitigation measures that may be approved into a SIP 
include limitations on fugitive dust during construction or street 
sweeping. Normal project design elements (dimensions, lane widths, 
materials, etc.), however, are not considered mitigation or control 
measures.

B. Rationale and Response to Comments

    Commenters were supportive of the proposal. The purpose of 
conformity is to ensure that federal actions are consistent with the 
SIP air quality objectives. If the approved SIP includes control 
measures for mitigating PM2.5 emissions from federal 
transportation projects, then conformity should include a written 
commitment from the project sponsor to include these SIP measures in 
the final plans, specifications, and estimates for the project. EPA 
believes that this requirement will help PM2.5 areas achieve 
clean air by ensuring that federal projects comply with control 
measures that result in air quality improvements as anticipated in the 
SIP. Although such projects must comply with SIP requirements in any 
event, documenting compliance in a conformity determination adds an 
important enforcement tool to aid in SIP compliance.
    Some commenters requested clarification that such control measures 
are not considered transportation control measures (TCMs) requiring 
timely implementation under 40 CFR 93.113. EPA is not changing the 
regulatory text in response to this comment. Not all control measures 
included in the SIP are TCMs. However, if a TCM is included in an 
approved PM2.5 SIP as a PM2.5 control measure, it 
must be implemented as required by the SIP and the conformity rule's 
timely implementation requirements. PM2.5 SIP control 
measures can include many different kinds of control measures, 
including TCMs as defined under Clean Air Act section 108 and Sec.  
93.101 of the conformity rule. EPA believes this clarification is 
consistent with current practice for implementing Sec. Sec.  93.117 and 
93.113 requirements in PM10 areas.
    One commenter generally supported EPA's proposal but was unsure how 
enforcement of PM2.5 SIP control measures would take place 
within the conformity process. This commenter recommended that 
enforcement of PM2.5 control measures be completed through 
the NEPA process, similar to the requirements for dealing with other 
environmental issues. EPA agrees that enforcement of PM2.5 
SIP control measures is important, but the conformity rule is the 
appropriate context for meeting Clean Air Act conformity requirements. 
If a SIP PM2.5 control measure is not implemented, then EPA 
believes it would not be appropriate to make a project-level conformity 
determination. Finally, it is

[[Page 40037]]

EPA's experience that implementation of Sec.  93.117 for 
PM10 areas has worked well within the framework of the 
existing conformity rule. For all of these reasons, EPA is finalizing 
the proposed Sec.  93.117 without further changes.

XII. PM2.5 Hot-Spot Analyses

    In the November 2003 proposal, EPA presented two options concerning 
hot-spot analyses in PM2.5 nonattainment and maintenance 
areas. One proposed option was to not require hot-spot analyses for 
FHWA and FTA projects in PM2.5 nonattainment and maintenance 
areas. The other proposed option was to require hot-spot analyses for 
such projects at certain types of locations if the SIP for the area 
identified any such locations. Under the second option hot-spot 
analyses would not be required for any projects before a SIP was 
submitted and then only if the PM2.5 SIP identifies 
susceptible types of locations.
    EPA received substantial comment on this portion of the November 
2003 proposal. After considering these comments, EPA, in consultation 
with DOT, has decided to request further public comment on these and 
additional options for PM2.5 hot-spot requirements. 
Therefore, EPA is not taking final action on this issue at this time. 
EPA will be publishing a supplemental notice of proposed rulemaking 
(SNPRM) on hot-spots in the near future. In that notice, EPA will be 
soliciting comment on additional options for addressing hot-spot 
analysis requirements in PM2.5 nonattainment and maintenance 
areas.
    EPA will address all comments received on PM2.5 hot-spot 
analysis requirements both in response to the November 2003 proposal as 
well as the future SNPRM on hot-spots in a final rulemaking after the 
close of the comment period for the SNPRM. EPA intends to complete its 
rulemaking on PM2.5 hot-spot requirements before 
PM2.5 nonattainment designations become effective.

XIII. PM10 Hot-Spot Analyses

    EPA also proposed several options for amending PM10 hot-
spot requirements in its November 2003 proposal. These options included 
maintaining the current conformity rule's hot-spot analysis 
requirements. A second option was to limit the analyses to certain 
circumstances. For example, only requiring analyses if the SIP has 
identified motor vehicle emissions as a localized problem. Under this 
scenario PM10 hot-spot analyses would not be required if the 
SIP determined that motor vehicle emissions do not cause localized 
problems. A third option was to limit PM10 hot-spot analyses 
to certain types of project locations. EPA also proposed an option to 
eliminate all PM10 hot-spot analysis requirements from the 
conformity rule.
    Similar to Section XII. on PM2.5 hot-spot requirements, 
EPA has decided to delay making a final decision on changes to the 
existing PM10 hot-spot analysis requirements, since EPA 
received substantial comment on the proposed options. In light of those 
comments and due to the close relationship between PM10 and 
PM2.5 hot-spot requirements, EPA and DOT have decided to 
propose additional options for PM10 hot-spot analyses in a 
future SNPRM for hot-spots. In that notice, we will solicit comment on 
additional options for addressing hot-spot analysis requirements in 
PM10 nonattainment and maintenance areas.
    EPA will address all comments received on PM10 hot-spot 
analysis requirements both in response to the November 2003 proposal 
and the future SNPRM in a final rulemaking after the close of the 
comment period for the SNPRM. EPA intends to complete rulemaking on 
PM10 hot-spot requirements before PM2.5 
nonattainment designations become effective. EPA notes, however, that 
the existing conformity rule's PM10 hot-spot requirements 
continue to remain in effect at this time. Until a final action is 
taken, PM10 nonattainment and maintenance areas will 
continue to meet the PM10 hot-spot requirements of 
Sec. Sec.  93.116 and 93.123 of the current conformity rule.

XIV. Federal Projects

A. Description of Final Rule

    Today's final rule is consistent with the June 30, 2003, proposal 
and the most recent EPA and DOT guidance implementing the March 2, 1999 
court decision. The final rule modifies Sec.  93.102(c) of the 
conformity rule so that no new federal approvals or funding commitments 
for non-exempt projects can occur during a transportation conformity 
lapse. A conformity lapse generally occurs if transportation plan and 
TIP conformity determinations are not made within specified time 
frames. During a conformity lapse no new conformity determinations for 
plans, TIPs, and FHWA or FTA non-exempt projects may be made. Under the 
new Sec.  93.102(c) provision, non-exempt transportation project phases 
can be implemented during a lapse if they have received all required 
FHWA or FTA approvals or funding commitments and have met associated 
conformity requirements before the lapse. However, no new federal 
approvals or funding commitments for subsequent or new project phases 
can be made during the lapse.
    EPA is making one minor revision to Sec.  93.102(c) in today's 
rulemaking that was not included in the June 30, 2003 proposal. 
Specifically, we are clarifying that Sec.  93.102(c) requirements do 
not have to be satisfied at the time of project approval for TCMs that 
are specifically included in an applicable SIP (provided that all other 
relevant transportation planning and conformity requirements are met). 
During the development of this final rule, EPA realized that the 
conformity rule Sec.  93.114(b), as amended on November 15, 1995 (60 FR 
57179), provided this exception for TCM project approvals during a 
conformity lapse. Therefore, EPA is including this exception in Sec.  
93.102(c) of today's action. EPA does not believe a reproposal is 
necessary to finalize this minor change to Sec.  93.102(c) as this 
revision will not change the requirements for federal funding and 
approval of projects and project phases as determined by the court and 
simply clarifies the relationship between existing Sec.  93.114(b) 
requirements and today's Sec.  93.102(c) revision. Areas should refer 
to the November 1995 rulemaking for more information on Sec.  93.114(b) 
requirements.
    As proposed, today's final rule also moves previous Sec.  
93.102(c)(2) requirements relating to approved projects to Sec.  
93.104(d) to limit redundancy and improve organization of the 
conformity rule. The conformity rule continues to require a new 
conformity determination when a significant change in a project's 
design concept and scope has occurred, a supplemental environmental 
document for air quality purposes is initiated, or three years have 
elapsed since the most recent major step to advance a project has 
occurred. A major step is defined in today's conformity rule as ``* * * 
NEPA process completion; start of final design; acquisition of a 
significant portion of the right-of-way; and construction (including 
Federal approval of plans, specifications and estimates)'' (40 CFR 
93.104(d)).
    See EPA's conformity website listed in Section I.B.2. to download 
an electronic copy of the June 30, 2003 proposal to this final rule and 
the latest EPA and DOT guidance implementing the court decision.

B. Rationale and Response to Comments

    EPA is revising the conformity rule in a manner consistent with the 
Clean Air Act, as interpreted by the court decision. Previously, 
section 93.102(c)(1) of the 1997 conformity rule

[[Page 40038]]

(62 FR 43780) allowed a highway or transit project to receive 
additional federal approvals and funding commitments during a lapse if 
the project came from a previously conforming plan and TIP, a 
conformity determination for the project had been made, and the NEPA 
process was completed before the lapse. In its decision, the court held 
that Sec.  93.102(c)(1) of the 1997 rule violated the Clean Air Act 
since it allowed such transportation projects (i.e., ``grandfathered'' 
projects) to receive further federal approvals or funding commitments 
during a lapse. As a result, the final rule allows projects and project 
phases to advance during a conformity lapse only if approvals or 
funding commitments for these projects and project phases were granted 
prior to the lapse.
    Most commenters supported EPA's proposal for advancing project 
phases during a conformity lapse and believed that DOT and EPA's 
interpretation of the court decision was appropriate. Two commenters 
also agreed that EPA's June 30, 2003 proposal is a better 
interpretation of the court decision than a previous interpretation 
reflected in a FHWA/FTA guidance document issued on June 18, 1999. The 
June 1999 guidance has since been revised and superceded by the January 
2, 2002 FHWA/FTA guidance. Under the FHWA/FTA January 2002 guidance 
document and today's final rule, any project phase (e.g., right-of-way 
(ROW) acquisition, final design or construction) that is authorized 
before a conformity lapse can be implemented during the lapse. However, 
no further approvals or funding commitments for subsequent project 
phases can occur during the lapse. See Section II. for further 
information regarding these guidance documents.
    EPA believes this change is appropriate because the court did not 
explicitly rule on the issue of how previously authorized project 
phases are affected during a lapse. Therefore, the court decision has 
led EPA and DOT to conclude that a project phase that previously 
receives all federal approvals and funding commitments can be 
implemented during a conformity lapse. EPA and DOT believe suspending 
such authorized commitments during a conformity lapse is not required 
by the Clean Air Act.
    Although most commenters understood that EPA's proposed rule 
revision is constrained by the court decision, a few commenters still 
expressed a preference for the previous rule's grandfathering 
provision. Specifically, one commenter stated that without the 
grandfathering provision, conformity lapses will lead to costly delays 
in infrastructure development and will waste valuable planning 
resources. Another commenter stated that the conformity process should 
be a forward-looking process and that once a project is included in a 
conforming plan and TIP, that project should be permanently 
``grandfathered'' until built, changed substantially or removed from 
the plan/TIP, as having previously satisfied all of its requirements 
under the Clean Air Act. Another commenter urged EPA to change the 
conformity rule so that projects can go forward during a conformity 
lapse once the environmental requirements pertaining to air quality in 
the NEPA process have been satisfied. This commenter questioned why 
project approvals and funding commitments that are unrelated to air 
quality (e.g., ROW acquisition) should be impacted by the conformity 
rule.
    As stated above, the court ruled that the previous rule's 
grandfathering provision did not meet Clean Air Act requirements since 
it allowed project approvals and funding commitments to be granted 
during a conformity lapse (i.e., when the transportation plan and TIP 
do not conform). Thus, this rule change is mandated by the court 
decision, as noted by most commenters. This decision has resulted in a 
process for advancing projects that is more protective of air quality 
than the previous rule's grandfathering provision. Although some 
project phases, such as ROW acquisitions, will not affect regional 
motor vehicle emissions by themselves, such phases are significant 
steps towards the eventual construction and operation of a 
transportation project. EPA believes that if unauthorized project 
phases are allowed to proceed during a lapse, federal approval and 
funding may be expended on projects that do not conform to the SIP's 
air quality goals.
    Also, EPA believes it is important to understand the practical 
impact and scope of eliminating the previous rule's grandfathering 
provision in most areas. This final rule will affect only those areas 
that are unable to meet a conformity deadline, and as a result, enter 
into a conformity lapse. This rule does not affect federal funding and 
approval of projects in areas that have a conforming plan and TIP in 
place and are meeting the conformity rule's requirements.

XV. Using Motor Vehicle Emissions Budgets From Submitted SIPs for 
Transportation Conformity Determinations

A. EPA's Role in the Adequacy Process

1. General Description of Final Rule
    Today's final rule continues to allow certain SIP budgets to be 
used for conformity before a SIP is approved. However, this final rule 
modifies several provisions under Sec. Sec.  93.109 and 93.118 of the 
conformity regulation to specify that EPA must affirmatively find 
submitted budgets adequate before they can be used in a conformity 
determination. The final rule also establishes the process by which EPA 
will review and make adequacy findings for submitted SIPs, as described 
in the June 30, 2003 proposal.
    Specifically, the final rule eliminates those provisions in 
Sec. Sec.  93.109 and 93.118(e) that required areas to use budgets from 
submitted SIPs 45 days after submission unless EPA had found them 
inadequate. Instead, today's rule stipulates that before a budget from 
a SIP submission can be used in conformity, EPA must find it adequate 
using the criteria in Sec.  93.118(e)(4). Under this final rule, a 
budget cannot be used until the effective date of the Federal Register 
notice that announces that EPA has found the budget adequate, which 
would be 15 days from the date of notice publication (unless the 
adequacy finding is included in EPA's final approval notice for the 
SIP; see Section XV.C.1 below for more information).
    This final rule also incorporates language from the November 5, 
2003 conformity proposal (68 FR 62690). EPA's November 2003 proposal 
was consistent with the June 30, 2003 proposal that addressed the March 
1999 court decision. However, the November 2003 proposal further 
clarified when the budget test would be required when EPA publishes a 
final approval or direct final approval of a SIP and budgets in the 
Federal Register. For more information on when approved budgets can be 
used in conformity determinations, see Section XV.C. of this final 
rule.
    Today's final rule addresses only the procedures for making 
adequacy findings for submitted SIPs in accordance with the court 
decision. The final rule does not change the criteria listed in Sec.  
93.118(e)(4) of the rule for determining the adequacy of submitted 
SIPs, as the court did not address this provision in its decision. The 
final rule is consistent with the June 30, 2003 proposed rule and the 
adequacy

[[Page 40039]]

procedures already in place as a result of EPA's May 14, 1999 guidance 
issued to implement the court decision. Therefore, existing adequacy 
procedures will generally remain the same as they have been since the 
1999 guidance was issued. EPA notes, however, that the June 30, 2003 
proposal and today's final rule include more detailed information on 
the implementation of the adequacy process and expand upon EPA's May 
1999 guidance. See Section II. of this notice for more background 
information on EPA's guidance document.
2. Rationale and Response to Comments
    In its ruling, the court remanded Sec.  93.118(e)(1) of the 
conformity rule to EPA for further rulemaking. This section of the 
conformity rule had allowed budgets to be used in conformity 
determinations 45 days after SIP submission even if EPA had not found 
them adequate. However, the court ruled that a submitted budget could 
only be used for conformity purposes if EPA had first found it 
adequate.
    Specifically, the court stated that ``where EPA fails to determine 
the adequacy of budgets in a SIP revision within 45 days of submission, 
* * * there is no reason to believe that transportation plans and 
programs conforming to the submitted budgets ``will not--(i) cause or 
contribute to any new violation of any standard in any area; (ii) 
increase the frequency or severity of any existing violation of any 
standard in any area; or (iii) delay timely attainment of any standard 
* * *'' 42 U.S.C. Sec.  7506(c)(1)(B).'' 167 F.3d, at 650. The court 
remanded Sec.  93.118(e)(1) to EPA so that it could be harmonized with 
these Clean Air Act requirements. EPA believes this final rule achieves 
the court's directive.
    Most commenters favored using submitted SIPs and budgets that have 
been found adequate before SIP approval in conformity determinations. 
Most commenters also supported EPA's proposal to incorporate the 
existing adequacy process into the conformity rule in accordance with 
the court decision. EPA received similar statements of support for our 
proposed adequacy process from one commenter that submitted comments on 
the November 5, 2003 proposal. Some commenters believed that the 
existing adequacy process provides certainty to the conformity process 
and ensures that submitted budgets are consistent with Clean Air Act 
requirements before they are used in conformity determinations. 
Additional comments on specific aspects of the adequacy process and 
EPA's responses to those comments can be found in Sections XV.B. 
through XV.F. below.

B. General Description of the Adequacy Process

1. Description of Final Rule
    The final rule adds a new provision, Sec.  93.118(f), to the 
conformity rule that provides the basic framework of the adequacy 
process. The new Sec.  93.118(f) generally reflects EPA's existing 
adequacy process as proposed in the June 30, 2003 rulemaking and 
described in EPA's 1999 adequacy guidance. The adequacy process 
consists of three basic steps: public notification of a SIP submission, 
a public comment period, and EPA's adequacy finding, including response 
to submitted comments. These three steps are described below. Section 
XV.B. of today's preamble specifically addresses the adequacy 
procedures listed in Sec.  93.118(f)(1) that will be used for submitted 
SIPs in most cases. Section XV.C. covers alternative procedures listed 
in Sec.  93.118(f)(2) for determining the adequacy of submitted SIPs 
through the SIP approval process.
    EPA will review the adequacy of submitted SIP budgets in cases 
where a budget can be used for conformity prior to approval. Adequacy 
reviews would be completed for the following cases:
     SIPs that are considered ``initial SIP submissions'' 
(generally the first SIP submission to meet a given Clean Air Act 
requirement). A discussion of ``initial SIP submissions'' can be found 
in the preamble of the proposed rule entitled, ``Transportation 
Conformity Rule Amendments: Minor Revision of 18-month Requirement for 
Initial SIP Submissions and Addition of Grace Period for Newly 
Designated Nonattainment Areas'' (August 6, 2002, 66 FR 50956-50957);
     Revisions to previously submitted but not approved SIPs; 
and
     Revisions to certain approved SIPs, as described further 
in Section XV.D.1. of today's action.

    For more information on the SIP submissions that EPA will review 
for adequacy, see the June 30, 2003 conformity proposal (68 FR 38982-
38984).
    Notification of SIP submissions: After a state officially submits a 
control strategy SIP or maintenance plan to EPA, we will notify the 
public by posting a notice on EPA's adequacy Web site and will attempt 
to do so within 10 days of submission. EPA's adequacy Web site is the 
central national location for adequacy information. Currently, the Web 
site is found at http://www.epa.gov/otaq/traq/traqconf/adequacy.htm. We 
will consider a SIP submission to be formally submitted on the date 
that the EPA regional office receives the official SIP. In addition, 
EPA will directly notify identified interested members of the public. 
If a member of the public would like to be notified when we receive a 
SIP submission for a particular state or area, he or she should contact 
in advance the EPA regional employee listed on the Web site for that 
state. EPA's Web site provides EPA regional contact information so that 
interested parties can arrange or discuss notification processes. For 
example, EPA could use postcards, letters, emails or phone calls to 
notify requesters, as agreed on by the interested party and EPA.
    Public comment: A 30-day public comment period will be provided at 
a minimum in either of the following cases:
     If the state has made the entire SIP submission 
electronically available to the public via a Web site, electronic 
bulletin board, etc., the 30-day comment period will start immediately 
upon the posting of the SIP notice on the EPA adequacy website. EPA 
will include a link to the state website in its public notification.
     If the SIP is not available via the Internet or is only 
available in part, if someone requests a paper copy of the entire SIP 
and EPA receives the request within the first 15 days after the SIP is 
posted, the 30-day public comment period will start on the date that 
EPA mails the requested copy of the SIP. However, if no one has 
requested a copy of the SIP from EPA within 15 days after the date of 
EPA posting notification, EPA will consider the 30-day comment period 
to have started immediately upon EPA's adequacy Web site posting.
    Our Web site will state when the public comment period begins and 
ends, and to whom to send comments. The adequacy Web site will also 
include information on how to obtain a copy of a SIP submission under 
adequacy review. EPA will not make SIP submissions electronically 
available on our adequacy Web site. If someone requests a copy of the 
SIP, the Web site will be updated to reflect any extension of the 
public comment period.
    EPA's adequacy finding: After a thorough review of all public 
comments received and evaluation of whether the adequacy criteria have 
been met, the appropriate EPA regional office will make a finding that 
the submitted SIP is either adequate or inadequate and send a letter 
indicating EPA's finding, including response to comments, to the state 
or local air agency and other relevant agencies such as the MPO and 
state transportation agency. The EPA

[[Page 40040]]

regional office will also mail or email a copy of the letter and 
response to comments to others who request it, as previously arranged.
    The EPA regional office will also subsequently announce the 
adequacy finding in the Federal Register. If EPA finds a budget 
adequate, it can be used for conformity determinations on the effective 
date as stated in the Federal Register notice, which will be 15 days 
after the notice is published. EPA will post EPA's adequacy letter, our 
response to any comments, and the Federal Register notice on the EPA 
adequacy Web site.
    Alternatively, in cases where EPA is conducting an adequacy review 
and moving quickly to rulemaking on a SIP, EPA may use the proposed or 
final rulemaking notice for a control strategy SIP or maintenance plan 
to announce our adequacy finding, instead of first sending a separate 
letter to the relevant agencies and following it with a Federal 
Register notice. In these cases, EPA would post our finding on the 
adequacy Web site, along with the relevant proposed or final rulemaking 
notice for the SIP that would include any response to comments.
    Adequate budgets must be used in all future conformity 
determinations for an area after the effective date of EPA's adequacy 
finding pursuant to Sec.  93.109 of today's final rule (or upon EPA's 
promulgation of a SIP approval as described in Section XV.C.I below); 
inadequate budgets cannot be used for conformity.
    EPA notes that two minor changes to the proposed regulatory text 
have been incorporated in this final rule regarding the procedures for 
EPA's adequacy process in Sec.  93.118(f)(1). First, EPA is clarifying 
in Sec.  93.118(f)(1)(iii) that EPA's response to comments received on 
the adequacy of a submitted SIP budget must be sent to the state along 
with EPA's letter that includes its finding. In the June 30, 2003 
proposal EPA stated that we will send our letter and response to 
comments to individuals who request a copy of these documents, but we 
did not specifically indicate that we would send a copy of the response 
to comments to the state. As a matter of practice, EPA does not issue 
adequacy findings through a formal letter to the state without 
including our responses to comments. Therefore, this minor 
clarification to the final rule language simply reflects how the 
adequacy process is currently being implemented.
    Second, EPA is also clarifying in Sec.  93.118(f)(1)(iii) that we 
will only review and consider any comments submitted through the state 
SIP process that are relevant to our adequacy finding. In Sec.  
93.118(f)(2)(iii) of the June 30, 2003 proposal EPA stated that we 
would respond to any comments submitted through the state process in 
the docket of our rulemaking to approve or disapprove a SIP (if 
adequacy is conducted through the SIP approval process). However, this 
language should be interpreted in context to refer only to comments 
relating to adequacy. If interpreted to apply to all comments on a 
submitted SIP, the language is not consistent with EPA's interpretation 
of existing requirements in Sec. Sec.  93.118(e)(5) \14\ or EPA's 
current process for adequacy findings of submitted SIPs and budgets 
that only require consideration of public comments addressing adequacy 
that were submitted through the state process. EPA and the states have 
separate established processes for taking action on a SIP and 
responding to all comments, including comments that relate to other 
aspects of a submitted SIP, that are received through those individual 
processes.
---------------------------------------------------------------------------

    \14\ August 15, 1997 final rule; 62 FR 43782.
---------------------------------------------------------------------------

    EPA believes that a reproposal is not necessary to make these two 
minor corrections in today's final rule. These minor revisions are 
consistent with EPA's original intentions and current practice of 
making adequacy findings.
    Finally, EPA intends to review the adequacy of a newly submitted 
budget through the process described above within 90 days of EPA's 
receipt of a full SIP submission in most cases. However, adequacy 
reviews could take longer particularly when EPA receives significant 
public comments. EPA will work with state and local agencies when 
adequacy findings can be expedited to meet conformity deadlines.
2. Rationale and Response to Comments
    EPA received a number of comments pertaining to different aspects 
of the proposed adequacy process. In particular, several commenters 
raised concerns about the length of time EPA has allocated to conduct 
adequacy reviews, indicating that 90 days is too long before submitted 
SIPs can become available for conformity purposes. Two commenters 
specifically urged EPA to commit sufficient staff and resources to 
ensure that adequacy determinations are timely. Some commenters 
suggested ideas for shortening the 90-day process by, for example, 
eliminating the 30-day public comment period and relying solely on the 
state's public involvement process for SIP development, or conducting 
adequacy reviews through parallel processing for all SIP submissions. 
Another commenter suggested eliminating the 15-day effective date for 
adequacy findings, since the adequacy process can be used to correct 
mistakes and later find budgets inadequate, if appropriate. In 
contrast, however, one commenter asked that the effective date be 
extended, as the current 15-day period does not allow sufficient time 
to prepare a petition for review and motion for stay in situations 
where a member of the public might disagree with EPA's finding. Other 
commenters suggested that parallel processing through the SIP approval 
process be used in all adequacy reviews to enable submitted SIPs to 
become available sooner in the conformity process.
    Two commenters that submitted comments on the November 5, 2003 
proposal requested that EPA commit to making adequacy findings during 
an explicit time period (e.g., 90 days) to ensure that conformity 
deadlines are met and to provide more predictability to the conformity 
process.
    After full consideration of all these comments, EPA believes that 
the current 90-day time frame for conducting adequacy reviews is 
appropriate and does not need to be modified. EPA believes that 
providing a 30-day public comment period that is focused entirely on 
the adequacy of a submitted SIP and that is separate from the state's 
public process is necessary to make an informed decision on the 
appropriateness of using a submitted SIP in the conformity process. In 
addition, we believe that the 15-day effective date is appropriate and 
should not be shortened or extended. We recognize that the public 
should be given some time to challenge EPA's finding before it becomes 
effective in cases where an individual disagrees with EPA's conclusion. 
We believe this time period before an adequacy finding becomes 
effective is necessary to ensure a fair and equitable process. However, 
EPA also understands the needs of conformity implementers to receive 
new air quality information for incorporation into the transportation 
planning and conformity processes in a timely manner. Therefore, EPA 
believes the existing adequacy process that provides a 15-day effective 
date best achieves these dual goals.
    EPA also wants to assure implementers that we are committed to 
conducting adequacy reviews, especially when such reviews are closely 
aligned with an upcoming conformity deadline, in an efficient and 
timely manner. However, as discussed in the June 30, 2003 proposal, 
some adequacy reviews that are complicated and draw a great deal of 
public interest

[[Page 40041]]

can take longer than 90 days. EPA is willing to conduct the adequacy 
review of any SIP submission through parallel processing to expedite 
our review and finding, if requested to do so by the state. Areas 
should use the interagency consultation process to consult on the 
development of SIPs and budgets and to determine whether parallel 
processing would expedite EPA's adequacy review so that conformity 
deadlines can be met in a timely manner.
    Two commenters disagreed with EPA's existing process for 
determining the adequacy of submitted SIPs, and instead believed that 
adequacy findings should be conducted through full notice and comment 
rulemaking. One of these commenters argued that, in difficult cases, 
the public needs to have the procedural protections required by 
Administrative Procedures Act (APA) rulemaking when EPA determines the 
adequacy of a submitted SIP for conformity purposes. The commenter also 
argued that under the existing adequacy process, EPA fails to include a 
statement of basis and purpose in a proposed action that would inform 
the public prior to submitting comments of the action that the Agency 
intends to take and the reasons supporting that action, as required by 
the APA. The commenter cites a pleading filed in a challenge to an 
adequacy finding that states that under the current adequacy process 
the public is given no advanced notice of whether EPA considers the SIP 
and budgets adequate, and if so, what criteria have been applied and 
what facts have been considered by EPA in its decision.\15\
---------------------------------------------------------------------------

    \15\ TRANSDEF v. EPA, 9th Circuit Court of Appeals, No. 02-
70443, Petitioners Motion for Stay, June 2002 at xxiii-xxiv.
---------------------------------------------------------------------------

    In response, EPA has always held that adequacy findings do not need 
to be made through APA notice and comment rulemaking. EPA does not 
believe these actions involve rulemaking, but rather they are conducted 
through informal adjudications. In the preamble to the 1997 conformity 
rule (62 FR 43783) EPA stated, ``it is appropriate not to provide 
notice and comment for adequacy determinations for submitted SIPs, 
since these determinations are only administrative reviews and not 
substantive rules.'' Adequacy reviews are carried out on an informal, 
case-by-case basis and apply existing criteria in the conformity rule 
(40 CFR 93.118(e)(4)) that were previously subjected to notice and 
comment rulemaking.\16\ Further, case law establishes that agencies 
have discretion to decide whether to conduct such actions through 
rulemaking or adjudication.\17\ Since the March 1999 court decision did 
not address this aspect of the adequacy process, EPA is not reopening 
this legal conclusion as stated in the 1997 conformity rule in today's 
action.
---------------------------------------------------------------------------

    \16\ July 9, 1996 proposed rule (61 FR 36112) and August 15, 
1997 final rule (62 FR 43780).
    \17\ See, NCRB v. Bell Aerospace Co., 416 U.S. 267,294 (1974).
---------------------------------------------------------------------------

    However, EPA believes that providing some opportunity for public 
involvement even in these adjudications adds value to our adequacy 
review. We believe public comment can assist us in making more informed 
decisions regarding submitted budgets and their ability to ensure that 
new transportation activities will not cause or contribute to new 
violations, worsen existing violations, or delay timely attainment of 
the air quality standards. As a result, the existing adequacy process 
that is included in today's final rule provides a minimum 30-day public 
comment period for each SIP that we review for adequacy. This adequacy 
public comment period, along with the state's public process during SIP 
development, allows EPA to make an informed decision through 
adjudication on whether a submitted SIP meets the adequacy criteria 
established under Sec.  93.118(e)(4) of the conformity rule.

C. Adequacy Reviews Through the SIP Process

1. Description of Final Rule
    EPA is finalizing procedures for conducting adequacy reviews and 
making adequacy findings through the SIP approval process in Sec.  
93.118(f)(2). EPA may use the SIP approval process to conduct our 
adequacy review when we are moving quickly to approve a SIP soon after 
it has been submitted. These rule revisions are consistent with the 
June 30, 2003 conformity proposal and EPA's May 1999 guidance that 
implements the court's decision. EPA is also clarifying in Sec.  93.109 
when the budget test must be satisfied as required by Sec.  93.118 if 
EPA finds SIP budgets adequate, and also if EPA approves SIPs and 
budgets through final and direct final rulemakings. This clarification 
to Sec.  93.109 is consistent with EPA's November 5, 2003 proposal.
    When EPA reviews the adequacy of a SIP submission simultaneously 
with EPA's approval of the SIP, the adequacy process will be 
substantially the same as that which we have outlined in Section 
XV.B.1. of this final rule as follows:
    Notification of SIP submission: In these cases, EPA will use a 
notice of proposed rulemaking to notify the public that EPA will be 
reviewing the SIP submission for adequacy. For example, we will notify 
the public of our adequacy review through the proposal notice when we 
are proposing to approve a SIP through parallel processing. In 
addition, when we make an adequacy finding for a SIP through direct 
final rulemaking, EPA will publish a proposed approval and a direct 
final approval in the Federal Register on the same day. In both the 
proposed and direct final rulemakings, EPA would announce the start of 
its adequacy review.
    Public comment: The publication of EPA's proposed approval notice 
(and direct final approval, when applicable) for a SIP submission will 
start a public comment period of at least 30 days. EPA will post the 
relevant proposed and direct final rulemakings on our Web site to 
notify the public when the comment period for adequacy, as well as for 
other aspects of the SIP, begins and ends. EPA will also include on the 
adequacy website information on how to obtain a copy of the SIP 
submission that EPA has proposed to approve and find adequate.
    EPA's adequacy finding: When we announce our adequacy review in a 
proposal notice only, we will subsequently issue our finding through 
either a letter to the state or through our final action on the SIP in 
the Federal Register. In the case where we issue our finding prior to a 
final action on the SIP, EPA will update the adequacy website to 
include the letter to the state that indicates our finding, responses 
to any comments received during the public comment period that are 
relevant to the adequacy of the SIP, and our separate adequacy notice 
that is published in the Federal Register in accordance with Sec.  
93.118(f)(1)(iii)-(v). Such findings will become effective 15 days 
after our published adequacy notice.
    In the case where we make our adequacy finding and address response 
to comments in a subsequent final rule that approves or disapproves the 
SIP, EPA will update the adequacy website with our finding as published 
in the final Federal Register approval or disapproval notice. In cases 
where EPA finds the budgets adequate when we approve a SIP, the budgets 
could be used for conformity purposes upon the publication date of the 
final approval action in the Federal Register. EPA is finalizing this 
clarification to Sec.  93.109 for each criteria pollutant covered by 
the current conformity rule, consistent with the November 5, 2003 
proposal. As stated in the November 2003 proposal, Clean Air Act 
section 176(c) requires that transportation activities conform to the 
motor vehicle emissions level established in the approved SIP.

[[Page 40042]]

Therefore, EPA believes that once a SIP is approved, its budgets must 
be used in future conformity determinations under the statute.
    When EPA conducts adequacy through direct final rulemaking, EPA's 
approval and adequacy finding generally become effective 60 days after 
publication according to the date indicated in the direct final Federal 
Register notice, provided that we receive no adverse comments and no 
other information or analysis changes EPA's position in that time 
period. However, if we receive adverse comments or our position changes 
as a result of further information or analysis, we will publish a 
notice in the Federal Register withdrawing our direct final action and 
adequacy finding prior to its effective date in most cases. In the case 
where EPA receives adverse comments that do not affect our adequacy 
finding, we could publish a notice that withdraws only our direct final 
approval of the SIP but retains our adequacy finding in the Federal 
Register prior to the effective date of the direct final rule. In any 
case, EPA will use its Web site to inform the public when the adequacy 
finding included in a direct final rule takes effect, or that we 
received comments that resulted in a withdrawal of all or part of our 
direct final approval action.
    Given the nature of the public comment process and effective date 
associated with direct final rulemaking, an adequacy finding cannot 
become effective until the effective date of the direct final rule. EPA 
is including this clarification in Sec.  93.109 of today's rule. This 
rule revision is consistent with the November 2003 proposal.
    Finally, consistent with language in Sec.  93.118(f)(1)(iii), EPA 
is clarifying in Sec.  93.118(f)(2)(iii) that when we conduct adequacy 
reviews through the SIP approval process, we will review and consider 
only those comments submitted through the state SIP process that are 
relevant to our adequacy finding (in addition to comments that are 
submitted through EPA's SIP approval process). In Sec.  
93.118(f)(2)(iii) of the June 30, 2003 proposal we stated that we would 
respond to any comments submitted through the state process in the 
docket of our rulemaking to approve or disapprove a SIP (if adequacy is 
conducted through the SIP approval process). However, as stated in 
Section XV.B.1. of today's action, one interpretation of this broad 
language could have implied that EPA would consider comments submitted 
through the state process beyond those comments relating to adequacy, 
which is not consistent with existing requirements or EPA's current 
adequacy process. Therefore, EPA believes that our final action 
clarifying this issue is a logical outgrowth of the proposal and that a 
reproposal is not necessary to make this minor correction limiting our 
consideration of comments submitted to the state to those comments 
relevant to the adequacy process in today's final rule.
2. Rationale and Response to Comments
    One commenter did not agree with the 60-day effective date of 
budgets that are found adequate and approved through direct final 
rulemaking. This commenter argued that the 60-day effective date for 
direct final rulemaking unnecessarily burdens conformity implementers 
with additional time requirements, as these budgets would have already 
undergone public comment through the state's approval process.
    EPA disagrees with this comment. When a SIP is found adequate and 
approved through direct final rulemaking (provided EPA receives no 
adverse comments), the 60-day effective date provides a 30-day public 
comment period and a 30-day time period for EPA to review any comments 
received and issue a withdrawal notice, if necessary. APA rulemaking 
procedures require EPA to provide a minimum 30-day public comment 
period when we approve a SIP through direct final rulemaking. In 
addition, EPA believes that providing a public comment period on our 
adequacy finding and SIP approval separate from the state's public 
process is necessary for EPA to make an informed decision on the 
appropriateness of using a submitted SIP in the conformity process. We 
also believe that the subsequent 30 days after the close of the 30-day 
public comment period is critical to review any comments we receive and 
decide whether any would change our approval of the SIP. If we receive 
comments that cause us to withdraw our direct final approval of the 
SIP, the subsequent 30 days is also necessary to perform the 
administrative tasks to ensure that the approval is withdrawn before it 
becomes effective. Areas should use the interagency consultation 
process to coordinate the introduction of new SIPs and budgets so that 
adequacy reviews can be completed and new budgets are available in time 
to meet any upcoming conformity deadlines.
    Another commenter suggested that adequacy reviews of all submitted 
SIPs could be accomplished through parallel processing procedures and 
direct final rulemaking to meet EPA's objective of incorporating 
submitted SIPs into the conformity process in a timely manner. This 
commenter was generally opposed to EPA's existing adequacy process and 
believed that EPA should use notice and comment rulemaking for all 
adequacy findings.
    EPA agrees with the comment that adequacy findings can be expedited 
through parallel processing procedures. Several states have requested 
such procedures to expedite EPA's adequacy findings since the 1999 
court decision. As stated in the June 2003 proposal, EPA will parallel 
process a SIP if requested to do so by the state. However, we should 
note that parallel processing can expedite the adequacy review of a 
submitted SIP only if no changes to that SIP and its budgets are made 
before the state officially submits the SIP to EPA for approval. In the 
event that the SIP significantly changes between the time EPA begins 
its initial adequacy review and the state's formal submission of the 
SIP, EPA would have to re-start the adequacy process once the new SIP 
is formally submitted.
    EPA does not believe, however, that direct final rulemaking would 
expedite the adequacy process for submitted SIPs in most cases. Under 
the situation the commenter has suggested, we would conduct our 
adequacy review and develop a proposed and direct final approval of our 
adequacy finding either at the same time that the state holds its 
public comment period (i.e., parallel processing) or after the SIP has 
been formally submitted to EPA. Once EPA completes its review and 
publishes the proposed and direct final rulemakings in the Federal 
Register, the budgets could not be used until 60 days after publication 
even if no adverse comments were received on EPA's direct final 
approval. If we received any relevant adverse comments, we would have 
to withdraw our direct final rule and publish a subsequent approval 
notice with response to comments.
    The purpose of the current adequacy process is to introduce new 
adequate submitted SIPs and budgets into the conformity process in a 
timely manner. EPA believes conducting all adequacy reviews through 
direct final rulemaking would defeat this purpose in many cases. EPA 
believes that conducting an adequacy review, preparing proposed and 
direct final rulemakings and providing a 60-day effective date (that 
includes a 30-day comment period), would require a time period much 
greater than the 90 days that EPA currently contemplates for the 
process. This required time period would significantly delay the use of 
adequate submitted budgets in conformity, especially in cases where EPA 
cannot

[[Page 40043]]

begin its adequacy review of a SIP until the state formally submits it 
to EPA for approval. Under the current adequacy process, EPA is able to 
complete its initial adequacy review concurrently with the adequacy 
public comment period, and thus, reduce the amount of time necessary to 
make an adequacy finding. Under direct final rulemaking, however, EPA 
would need to complete its adequacy review of submitted budgets before 
it could prepare and publish both a proposed approval and direct final 
approval of the budget's adequacy.
    In addition, direct final rulemaking is typically used only when an 
approval is straight-forward and no adverse comments are expected. In 
cases where SIPs are more controversial and adverse comments are 
received, the use of direct final rulemaking could delay the use of 
adequate budgets in the conformity process if EPA is required to spend 
time withdrawing its direct final approval and publish a subsequent 
final approval notice in the Federal Register with response to comments 
some time significantly later.
    For information on EPA's position regarding the general need to 
find submitted SIPs adequate through notice and comment rulemaking, see 
Section XV.B.2. above.

D. Use of Submitted Revisions to Approved SIPs

1. Description of Final Rule
    EPA is also finalizing a minor clarification to a sentence in Sec.  
93.118(e)(1), consistent with the June 30, 2003 conformity proposal. 
Paragraph Sec.  93.118(e)(1) of today's rule clarifies that a budget 
from a submitted SIP cannot be used for conformity if an area already 
has an approved SIP that addresses the same pollutant and Clean Air Act 
requirement (e.g., rate-of-progress or attainment for a given air 
quality standard), and that approved SIP has budgets established for 
the same year as the submitted SIP.
2. Rationale and Response to Comments
    EPA received a number of comments on the issue of using submitted 
SIPs in conformity once an approved SIP has already been established. 
Several commenters encouraged EPA to amend the conformity rule to allow 
adequate budgets to supercede approved budgets in all cases or when EPA 
believes it to be justified. One commenter that submitted comments on 
the November 5, 2003 proposal requested further clarification on when 
adequate budgets replace existing approved budgets. This commenter 
indicated that there has been confusion over this aspect of the rule 
and believed that requiring adequate budgets to be fully approved 
before they can replace existing approved budgets would be burdensome 
and would defeat the purpose of the adequacy process. In contrast, 
another commenter expressed concern over the use of submitted SIPs in 
conformity determinations when an approved SIP for the same year and 
Clean Air Act requirement already exists.
    EPA believes that Clean Air Act section 176(c) clearly requires 
transportation plans, TIPs and projects to conform to a nonattainment 
or maintenance area's approved SIP before such activities can be funded 
or approved. Therefore, EPA believes it has no statutory authority to 
allow submitted budgets that are established for the same year and 
Clean Air Act requirement to supercede budgets that have already been 
approved into the SIP. In general, a submitted budget replaces a 
previously approved budget established for the same year and Clean Air 
Act requirement only after EPA has approved the submitted budget. EPA 
notes, however, that submitted budgets that are established for a 
different year or Clean Air Act requirement than a previously approved 
budget must be used in conformity upon EPA's adequacy finding, along 
with all other applicable adequate and approved budgets. Thus, EPA 
cannot agree with commenters' request to allow submitted SIPs to 
supercede approved SIPs in all cases.
    However, there have been cases where, based on unique 
circumstances, EPA has agreed to a state's request to limit our 
approval of a SIP in such a manner that a revision to that SIP could be 
used upon the effective date of EPA's adequacy finding. Also, EPA has 
limited its approval of certain serious and severe 1-hour ozone 
attainment SIPs so that updated adequate SIP budgets based on the 
MOBILE6 emissions factor model could be used prior to EPA's 
approval.\18\ In these cases, EPA has limited its approval of the 
original SIP so that the budgets included in that SIP are no longer 
considered ``approved'' upon the effective date of our subsequent 
adequacy finding for the revised SIP. EPA concludes that such actions 
to limit the approval of a SIP are permitted under the Clean Air Act 
and conformity rule, as both the statute and regulations only require 
the use of approved SIPs and budgets in the conformity process.
---------------------------------------------------------------------------

    \18\ November 8, 1999, Memorandum from Lydia N. Wegman, Director 
of the Air Quality Standards and Standards Division of EPA's Office 
of Air Quality Planning and Standards, and Merrylin Zaw-Mon, then-
Director of the Fuels and Energy Division of EPA's Office of Mobile 
Sources, to Air Director, Regions I-VI, ``1-Hour Ozone Attainment 
Demonstrations and Tier 2/Sulfur Rulemaking.''
---------------------------------------------------------------------------

    Another commenter objected to the continued use of submitted SIPs 
in conformity altogether, arguing that such SIPs lacked sufficient 
authority and validity to provide the basis for a conformity test in 
the absence of an approved SIP. At a minimum, the commenter suggested 
that in cases where a submitted SIP is used in conformity, the final 
rule should require that any transportation project approved on the 
basis of that submitted SIP should be subject to rescission, until the 
SIP itself is finally approved. Under circumstances where a SIP is 
submitted and found adequate, but subsequently found inadequate or 
disapproved, the commenter believed that this subsequent action on the 
SIP should reverse the approval of highway capacity increasing projects 
that received approval or funding after having conformed to budgets 
that are ultimately found inadequate or disapproved.
    EPA disagrees with these comments. When no adequate or approved 
budgets are available for conformity purposes, the interim emissions 
tests (i.e., the build/no-build test and/or the baseline emissions 
tests) in Sec.  93.119 must be met to fulfill the conformity 
requirements. EPA, along with most stakeholders, prefers the use of 
submitted adequate SIPs and budgets for conformity rather than the 
interim emissions tests provided by Sec.  93.119\19\ because we believe 
that submitted SIPs and budgets are a better measure of emissions, 
consistent with attaining and maintaining a given standard and 
pollutant. Submitted SIPs and budgets that EPA has found adequate 
should be based on the most recent data and models available at the 
time the SIP is developed and should reflect accurate estimates of 
emissions that are consistent with attaining or maintaining a given 
pollutant and standard. Therefore, EPA believes that a submitted SIP 
for an applicable standard that satisfies the adequacy criteria in 
Sec.  93.118(e)(4) provides a reasonable basis for ensuring that 
transportation activities do not worsen existing violations, create new 
violations or delay timely attainment of the relevant air quality 
standard.
---------------------------------------------------------------------------

    \19\ August 15, 1997, 62 FR 43781-43783.
---------------------------------------------------------------------------

    Furthermore, EPA concludes that the use of submitted SIPs is 
supported by the Clean Air Act. Before a SIP has been submitted and 
approved by EPA, the Clean Air Act section 176(c)(3) requires

[[Page 40044]]

that transportation plans and TIPs must be consistent with the most 
recent estimates of mobile source emissions, provide for the 
expeditious implementation of TCMs in approved SIPs, and contribute to 
the attainment of the air quality standards in certain ozone and CO 
areas. Clean Air Act section 176(c)(1) also requires that 
transportation activities not worsen violations or delay timely 
attainment of the air quality standards. Because the adequacy criteria 
require submitted budgets to be consistent with progress and attainment 
requirements, we believe that conformity determinations based on 
submitted budgets that have been reviewed and found adequate by EPA 
through the adequacy process meet these statutory requirements in cases 
where an approved budget does not exist for the same year and Clean Air 
Act requirement. In addition, EPA believes that the use of a submitted 
adequate budget for a given air quality standard serves the Clean Air 
Act's goals for that standard better than either of the interim 
emissions tests. This position regarding the use of submitted SIPs in 
conformity in the absence of an approved SIP has also been endorsed by 
a court in 1000 Friends of Maryland v. Carol Browner, et al., 265 F.3d 
216 (4th Cir. 2001).
    EPA also notes that in situations where a SIP has not yet been 
approved, the March 1999 court decision did not find the use of 
submitted budgets in conformity unlawful. In its decision, the court 
only ruled against the use of submitted SIPs that EPA had failed to 
affirmatively find adequate for conformity purposes. In the absence of 
EPA's adequacy finding, the court believed that there is no assurance 
that transportation activities would not cause new violations, increase 
the severity of existing violations or delay the timely attainment of 
an air quality standard. However, the court did not make a similar 
finding in the case where EPA has found a budget adequate. As a result 
of this decision, EPA developed the existing adequacy process to ensure 
that submitted SIPs and budgets are appropriate for use in the 
conformity process, while still retaining the flexibility of the 1997 
conformity rule that allows submitted SIPs to be used in a timely 
manner in place of the interim emissions tests.
    EPA also disagrees with the commenter's suggestion that 
transportation project approvals that conform to an adequate budget 
should be subject to rescissions in the event that the SIP and motor 
vehicle emissions budgets are later found inadequate or disapproved. We 
believe that such an approach would cause significant confusion and 
only serve to severely disrupt the transportation planning and 
conformity processes. EPA has always regarded conformity as a 
prospective and iterative process. EPA believes that a conformity 
determination that meets the Clean Air Act and conformity rule's 
requirements at the time the determination is made should remain valid, 
regardless of whether the SIP and budgets on which that determination 
is based are subsequently found to be inadequate or disapproved. Since 
1997, Sec.  93.118(e)(3) and Sec.  93.120(a)(1) of the conformity rule 
have provided for conformity determinations based on budgets that are 
subsequently found inadequate or disapproved to remain in effect, and 
in overturning Sec.  93.118(e)(1) and Sec.  93.120(a)(2) of the rule, 
the court did not indicate any concern with these other provisions.
    In the limited case where a transportation plan and TIP have been 
found to conform to applicable budgets that are later found inadequate 
or disapproved, such budgets could no longer be used in future 
conformity determinations once the disapproval or inadequacy finding 
becomes effective. In the next conformity determination, emissions 
projected from the transportation plan and TIP, together with emissions 
projected from the existing transportation network, would have to meet 
new and/or existing budgets that have been found adequate or approved, 
or if no budgets are available, the interim emissions test(s) in Sec.  
93.119.\20\ As a result, the next conformity determination would ensure 
that the emissions from all on-road transportation sources would again 
be consistent with the area's goals for attaining or maintaining the 
air quality standards. In that determination, projected emissions 
reflecting projects that were approved based on the previous inadequate 
or disapproved SIP would have to be taken into account, before the plan 
and TIP could again conform. EPA believes these existing requirements 
and the iterative nature of the conformity process will address any of 
the above concerns.
---------------------------------------------------------------------------

    \20\ EPA also notes that upon the effective date of a SIP 
disapproval without a protective finding, an area would enter into a 
``conformity freeze.'' During a conformity freeze, only projects in 
the first three years of the current conforming plan and TIP can 
proceed. No plan and TIP conformity determinations can be made until 
a new control strategy SIP revision fulfilling the same Clean Air 
Act requirement as that which EPA disapproved is submitted, and EPA 
finds the motor vehicle emissions budgets in that SIP adequate for 
conformity purposes or approves the new revision. For more 
information on conformity freezes and the consequences of a SIP 
disapproval without a protective finding, see Section XVII. of this 
final rule.
---------------------------------------------------------------------------

E. Changing a Previous Finding of Adequacy or Inadequacy

1. Description of Final Rule
    As explained in the June 30, 2003 conformity proposal, EPA can 
change an adequacy finding from adequate to inadequate or from 
inadequate to adequate for a specific reason such as receiving new 
information or conducting further review and analyses that affect our 
previous finding. For example, EPA might change a finding of inadequacy 
if a state submits additional information that clarifies or supports 
the adequacy of the submitted SIP and budget. In this case, EPA will 
treat the additional information as a supplement to the previous SIP 
submission, and would post a notice on the adequacy Web site and begin 
a new 30-day public comment period on the entire SIP including this new 
information. After reviewing any comments, we would make a new finding, 
as appropriate, in accordance with those procedures in Sec.  93.118(f) 
of this final rule.
    We could change our finding to inadequate in the case where we find 
the budgets in a submitted SIP adequate but later discover based on 
additional information or further review that they do not meet the 
criteria for adequacy. EPA requested comment in the June 30, 2003 
proposal on whether the public should be provided an opportunity to 
comment on any new information before a subsequent finding of 
inadequacy becomes effective in cases where EPA reconsiders its initial 
finding of adequacy.
    Based on comments received, the final rule does provide for a 
subsequent public comment period of at least 30 days in cases where EPA 
believes the public could provide helpful insight and analysis for 
determining whether an initial finding of adequacy should be changed 
because of new information. In such cases, EPA would re-post the SIP on 
the adequacy Web site and start another minimum 30-day public comment 
period. EPA would also provide an explanation of how the new 
information has caused us to reconsider our initial adequacy finding. 
After evaluating any comments received during the public comment 
period, EPA will determine whether the submitted SIP is inadequate 
using the adequacy procedures described in either Sec.  93.118(f)(1) or 
(f)(2) of today's rule. In cases where EPA reverses its previous 
finding to a finding of inadequacy using procedures in Sec.  
93.118(f)(1), such findings would become effective

[[Page 40045]]

immediately upon the date of EPA's letter to the state. EPA believes 
this is necessary to prevent further use of inadequate budgets. Under 
Sec.  93.118(f)(1), we would also publish a notice of our inadequacy 
finding in the Federal Register and announce our finding on EPA's 
adequacy Web site.
    However, the final rule does not provide for a subsequent comment 
period under certain circumstances where it is obvious that a budget 
has become inadequate. For instance, if a state has submitted a new SIP 
indicating that the prior SIP submission no longer provides for 
attainment, it would be clear that the prior submission is inadequate. 
The final rule allows EPA to proceed on a case-by-case basis using the 
adequacy procedures described in Sec.  93.118(f)(1) to make a finding 
of inadequacy effective immediately by explaining these facts in a 
letter to the state. In this case, EPA would also publish a Federal 
Register notice of that finding and post it on the adequacy Web site. 
EPA believes that in such situations public comment would not be 
necessary or in the public interest. Rather, it would be more important 
for EPA to complete the adequacy process quickly and limit further use 
of such clearly inadequate budgets in the conformity process.
2. Rationale and Response to Comments
    EPA received four comments on whether an additional public comment 
period should be provided before EPA can reverse an initial adequacy 
finding to a finding of inadequate. Three of these commenters supported 
a public comment period of at least 30 days in these cases, with two of 
the commenters specifically stating that the additional time provided 
by the comment period could facilitate the completion of a conformity 
determination based on a previously adequate budget prior to the budget 
being deemed inadequate. One commenter, however, agreed with EPA's 
position that it is not always in the best interest of public health to 
delay an inadequacy finding until after a public comment period on new 
information has concluded.
    Based on these comments, EPA is promulgating a final rule that 
would provide at least a 30-day public comment period in certain cases 
where new information is subjective and does not provide a clear answer 
as to whether the submitted SIP is still adequate. In these cases, EPA 
believes that soliciting public comment is appropriate and could 
provide helpful insight and analysis on determining the impact of the 
new information on the adequacy of a submitted SIP. However, under this 
final rule, EPA would not provide a public comment period in cases 
where it is obvious that a budget has become inadequate. EPA believes 
this approach to the final rule would serve to protect the public 
health while still preserving the role of public involvement in the 
adequacy process. Under this final rule, EPA will proceed on a case-by-
case basis to determine whether new information for a submitted SIP 
budget warrants an additional public comment period, if such 
information causes us to reconsider our initial finding of adequacy.
    One commenter also suggested that EPA investigate the necessity of 
even having to make a finding of inadequacy for SIPs that EPA has 
previously found adequate. The commenter argued that since the court 
directed EPA to make a formal adequacy finding for a submitted SIP 
before it can be used in a conformity determination, the SIP approval 
process could subsequently be used to further review the adequacy of 
the SIP's budgets. In cases where further review or additional 
information reveals that an adequacy finding is no longer appropriate, 
EPA assumes from this comment that a subsequent finding of inadequacy 
would be issued through a SIP approval or disapproval action.
    EPA agrees that in some cases the SIP approval or disapproval 
process could be used to issue a subsequent finding of inadequacy for a 
SIP that was previously found adequate. However, in other cases, we 
believe that issuing a subsequent finding of inadequacy prior to EPA's 
approval and/or disapproval action for the SIP is necessary to protect 
public health. In most cases, EPA conducts a lengthy and detailed 
review of a submitted SIP as part of the SIP approval process. This 
review involves an evaluation of many aspects of the SIP that are not 
directly related to the motor vehicle emissions budgets. In situations 
where new information becomes available that clearly indicates that the 
budgets in a submitted SIP are inadequate prior to EPA's completed 
review of the entire SIP, we may determine that it is in the best 
interest of public health to issue a separate finding of inadequacy 
before going forward with a SIP approval and/or disapproval action. As 
a result, this final rule reserves EPA's ability to change a previous 
finding to a finding of inadequacy as provided by the existing adequacy 
process with public comment where the Agency deems necessary.

F. Adequacy Provisions Not Affected by This Rulemaking

1. Description of Final Rule
    This final rule does not change any of the existing adequacy 
criteria in the conformity regulation (Sec.  93.118(e)(4)). 
Furthermore, the rule continues to provide that reliance on a submitted 
budget for determining conformity is deemed to be a statement by the 
MPO and DOT that they are not aware of any information that would 
indicate that emissions consistent with such a budget would cause or 
contribute to any new violation, increase the frequency or severity of 
an existing violation, or delay timely attainment of the relevant 
standards (Sec.  93.118(e)(6)). These provisions were not affected by 
the court decision; therefore, EPA did not address these provisions in 
this rulemaking.
2. Rationale and Response to Comments
    One commenter objected to an alleged presumption inherent in Sec.  
93.118(e)(6) of the conformity rule. Prior to EPA's approval of a SIP, 
Sec.  93.118(e)(6) requires the MPO and DOT's conformity determination 
to be considered a statement that the MPO and DOT are not aware of any 
information that would indicate that emissions consistent with a 
submitted SIP would violate the Clean Air Act's requirements that 
transportation activities not cause or worsen a violation or delay 
timely attainment of the air quality standards. The commenter stated, 
however, that this presumption may not lawfully be substituted for the 
affirmative determination that an MPO is required to make under Clean 
Air Act section 176(c)(2)(A) or that DOT is required to make under 
Clean Air Act section 176(c)(1). The commenter also indicated that the 
regulatory requirement in Sec.  93.118(e)(6) effectively relieves MPOs 
and DOT of meeting these statutory requirements before a SIP has been 
submitted or after a SIP has been approved. In the commenter's opinion, 
this provision implies that EPA assumes the statutory criteria are 
satisfied if a budget is from an approved SIP, and therefore, silently 
waives any requirement that these criteria be addressed in such cases. 
The commenter also argued that the budget test demonstrated for select 
analysis years over the time frame of a transportation plan does not 
fully satisfy the statutory requirement that transportation activities 
conform to the SIP and not cause or worsen air quality violations in 
every year consistent with Clean Air Act section 176(c)(1)(A) and (B).

[[Page 40046]]

    In this rulemaking, EPA did not propose any changes to the rule's 
existing Sec.  93.118(e)(6) provision. Therefore, EPA cannot address 
this comment in today's final rule and is not re-opening this aspect of 
the conformity rule in this action.
    Furthermore, EPA does not agree that there is a presumption 
inherent in Sec.  93.118(e)(6) of the rule, nor do we agree with the 
commenter's interpretation of Sec.  93.118(e)(6) as it relates to the 
statutory requirements before a SIP is submitted and after a SIP has 
been approved. When EPA established the Sec.  93.118(e)(6) requirement 
in the 1997 conformity rule, we did so as another ``check'' to ensure 
that submitted SIPs and budgets are appropriate to use in conformity 
determinations before such SIPs and budgets are approved. EPA's 
adequacy review is a cursory review of the SIP and motor vehicle 
emissions budgets to ensure that the minimum adequacy criteria are met 
before a submitted SIP is used in a conformity determination. 
Therefore, we included Sec.  93.118(e)(6) in the 1997 final rule to 
share responsibility with the MPO and DOT for ensuring that the use of 
submitted budgets would not cause or contribute to any new violation; 
increase the frequency or severity of any existing violation; or delay 
timely attainment of the air quality standards. This provision 
clarifies that, in the absence of an EPA approved SIP, the MPO and DOT 
may not base conformity determinations on submitted SIPs that they have 
reason to believe do not satisfy Clean Air Act requirements.
    Once EPA has approved a SIP, however, we have always held that 
conformity to that approved SIP fulfills the Clean Air Act's conformity 
requirements. Section 176(c)(2)(A) of the Act specifically requires 
conformity determinations to show that ``emissions expected from 
implementation of such plans and programs are consistent with estimates 
of emissions from motor vehicles and necessary emission reductions 
contained in the applicable implementation plan.'' Consistent with the 
Clean Air Act, section 93.101 of the conformity rule defines an 
``applicable implementation plan'' as the portion(s) of a SIP, or most 
recent revision thereof, that has been approved by EPA. When EPA 
approves a SIP it is because we have concluded that the SIP and budgets 
are consistent with the SIP's purpose for attaining or maintaining a 
given air quality standard. Thus, since EPA promulgated the original 
conformity rule in 1993 (58 FR 62188), the budget test has been the 
mechanism that EPA believes is appropriate for meeting the statutory 
requirements for demonstrating conformity once a SIP becomes available 
for conformity purposes. Other tests or analyses in addition to the 
budget test have never been required by the conformity rule once a SIP 
is approved and EPA has not reopened this issue in this rulemaking.
    EPA also disagrees with the commenter's statement that the 
conformity rule's current budget test and regional emissions analysis 
year requirements are inconsistent with the Clean Air Act. The Clean 
Air Act does not address the specific time frame or years in which 
conformity emissions tests or analyses must be conducted. Since the 
November 24, 1993 conformity rule (58 FR 62188), EPA has maintained 
that once a budget becomes available for conformity purposes a 
demonstration of conformity for specific budget test years as described 
in Sec.  93.118 is sufficient for meeting the Clean Air Act 
requirements and ensuring that emissions from transportation activities 
do not cause violations, worsen existing violations or delay timely 
attainment of the air quality standards. In addition, EPA has always 
held that prior to a submitted SIP, the interim emissions tests as 
required by Sec.  93.119 of the current rule are also appropriate for 
meeting the statutory requirements (58 FR 62188).
    Conducting conformity determinations, including regional emissions 
analyses to satisfy Sec. Sec.  93.118 and 93.119 requirements, demands 
a significant amount of state and local resources. Therefore, EPA 
believes it would be impractical and overly-burdensome to require MPOs 
and state transportation agencies to conduct the applicable conformity 
test and regional emissions analysis for every year of a 20-year 
transportation plan. Based on EPA's interpretation of the Clean Air 
Act, we believe that the current rule's conformity test and emissions 
analysis year requirements are consistent with the statute, reasonable 
to implement and protective of public health. Again, EPA has not 
reopened this aspect of the conformity rule in this rulemaking, 
although we are clarifying Sec.  93.118 as described in Section XXIII. 
of this final rule.
    The same commenter also expressed concern over how EPA has applied 
the adequacy criteria established in Sec.  93.118(e)(4) of the 
conformity rule to certain submitted SIPs. Specifically, the commenter 
objected to adequacy findings for submitted SIPs that, (1) lack a 
control strategy that identifies all the control measures needed for 
reasonable further progress, attainment or maintenance, or (2) lack 
either fully adopted measures that satisfy the requirements of 40 CFR 
51.121 or written commitments to adopt specific measures that have been 
conditionally approved pursuant to Clean Air Act section 110(k)(4). The 
commenter argues that EPA has failed to adhere to the requirements of 
the Clean Air Act and conformity rule when we issue adequacy findings 
for submitted SIPs that rely on enforceable commitments to adopt 
additional control measures. In cases where additional mobile source 
controls are needed to satisfy a SIP's enforceable commitments, the 
commenter believed that the motor vehicle emissions budgets in such 
SIPs cannot be adequate to provide for attainment, since the budgets do 
not reflect the emissions reductions from the additional measures. As a 
result, the commenter requested that EPA clarify that enforceable 
commitments may not be relied upon to make an adequacy finding for SIPs 
that fail to contain sufficient, adopted, enforceable control measures 
to meet the statutory requirements for reasonable further progress, 
attainment or maintenance. The commenter believed that such a 
clarification would reaffirm the conformity rule's requirements that 
only SIPs that contain sufficient control measures to demonstrate 
attainment can be found adequate.
    In this rulemaking, EPA did not propose changes or clarifications 
to the existing adequacy criteria listed in Sec.  93.118(e)(4). This 
rulemaking only addresses the process by which EPA finds submitted SIPs 
adequate for conformity purposes, in accordance with the March 1999 
court decision. The existing adequacy criteria were established in the 
1997 conformity rule (62 FR 43780) and were not impacted by the court 
decision. Therefore, EPA is not revising these criteria nor reopening 
this aspect of the conformity rule in this action.
    EPA also disagrees with the commenter's position that SIPs that 
rely on enforceable commitments fail to meet the adequacy criteria 
established in Sec.  93.118(e)(4) of the rule. Section 93.118(e)(4) of 
the conformity rule does not require that all necessary control 
measures be identified and adopted to find a submitted SIP adequate. 
The adequacy criteria in the conformity rule only requires a budget to 
come from a submitted SIP that provides for reasonable further 
progress, attainment or maintenance of a given standard. The relevant 
section of the rule, Sec.  93.118(e)(4)(iv), states that a submitted 
SIP is adequate if: ``The motor vehicle emissions budget(s), when 
considered together with all other emissions

[[Page 40047]]

sources, is consistent with applicable requirements for reasonable 
further progress, attainment, or maintenance * * *''. This provision of 
the rule only requires that the total emissions allowed by the SIP, 
including the motor vehicle emissions budgets, are consistent with the 
Clean Air Act's purpose of the SIP (e.g., attainment). This provision 
of the rule does not require a submitted SIP to include all of the 
specific control measures necessary to meet its statutory purpose.
    Furthermore, EPA disagrees with the commenter that budgets from 
SIPs that include enforceable commitments cannot be adequate to provide 
for attainment. Clean Air Act provisions that address control strategy 
SIPs, such as sections 110(a)(2)(A), 172(c) and 182, require SIPs to 
contain a control strategy that provides sufficient emission reductions 
to demonstrate attainment by the statutory deadline. EPA believes that 
the use of enforceable commitments as a limited part of an overall 
control strategy for a SIP is reasonable and consistent with these 
provisions of the Clean Air Act. Therefore, EPA believes that where we 
approve or find adequate a SIP control strategy that includes an 
enforceable commitment, EPA's approval or adequacy finding for the 
motor vehicle emissions budgets in such a SIP would also be 
appropriate. EPA believes that as long as the budgets, in addition to 
all other emission sources and controls identified in the SIP 
(including any enforceable commitments), are consistent with a SIP's 
purpose of attaining or maintaining a given air quality standard, 
conformity to such budgets will also be consistent to the SIP's clean 
air goals.
    EPA also believes that SIPs that include enforceable commitments 
are consistent with both 40 CFR 51.121 relating to SIP control measures 
and Clean Air Act section 110(k)(4) requirements regarding conditional 
approvals. 40 CFR 51.281 requires that in cases where a SIP relies on a 
specific regulation as the basis for emissions reductions, that 
regulation must be properly adopted and copies of it must be submitted 
to EPA. This provision, however, does not require SIPs to consist only 
of rules that have been enacted as regulations and has no bearing on 
our ability to find a submitted budget adequate for conformity 
purposes. Clean Air Act section 110(k)(4) gives EPA the authority to 
conditionally approve a SIP that contains a commitment to adopt 
``specific enforceable measures.'' Such a conditional approval 
automatically converts to a disapproval if the measures are not adopted 
within one year, and thus the commitment itself is not enforceable. EPA 
believes, however, that SIPs that include adopted control measures as 
well as the enforceable commitment to identify and adopt additional 
measures can be found adequate and fully approved if such commitments 
meet various criteria and will achieve sufficient emission reductions 
to meet Clean Air Act deadlines and attain or maintain the air quality 
standards. In these cases, such commitments may extend beyond one year 
and are enforceable against the state if the state fails to meet the 
commitment by the specified time frame. EPA believes that it is 
appropriate to consider and approve the use of qualified enforceable 
commitments in cases where a state is not able to identify currently 
feasible measures to fill a small gap of needed emissions reductions.
    EPA's current policy for approving SIPs that are based on 
enforceable commitments was recently upheld in a decision by the court 
of appeals, BCCA Appeal Group, et al., v. U.S. EPA, et al., 348 F.3d 93 
(5th Cir. 2003). A complete discussion of our position on the use of 
enforceable commitments can be found in EPA's briefs in BCCA Appeal 
Group, et al., v. U.S. EPA, et al., 5th Cir. No. 02-60017, September 
20, 2002, at 115-146 and TRANSDEF, et al., v. EPA, et al., 9th Cir. No. 
02-7044, Respondent EPA's Second Supplemental Memorandum, August 22, 
2002, at 4-7. In addition, EPA's complete response to these comments 
pertaining to conformity rule provisions that are not addressed in this 
rulemaking can be located in the response to comments document for this 
final rule. Copies of all these documents are located in the public 
docket for this rulemaking listed in Section I.B. of today's action.
    Finally, one commenter stated that EPA should consider the entire 
SIP when determining adequacy of the budgets, as not doing so may 
permit conformity determinations to rely on SIPs that contain 
substantive flaws in inventories and control strategies for other 
sources. EPA would like to clarify that when we conduct an adequacy 
review of a submitted SIP, we always consider the SIP in its entirety 
as well as the budgets in that SIP. Section 93.118(e)(4)(iv) of the 
conformity rule requires that ``the motor vehicle emissions budget(s), 
when considered together with all other emissions sources, is 
consistent with applicable requirements for reasonable further 
progress, attainment, or maintenance * * *''. Therefore, EPA is 
required to consider emissions from other sources and their 
contribution towards meeting the purpose of the SIP before issuing an 
adequacy finding. Furthermore, some SIPs such as limited maintenance 
plans and those SIPs that qualify for EPA's insignificance policy do 
not contain budgets where certain findings are made. In these cases, 
EPA also focuses on the entire SIP and how such SIPs qualify for these 
specific policies. See the June 30, 2003 proposal to this final rule 
(68 FR 68983-4) for more information about EPA's adequacy review of 
SIPs that do not contain motor vehicle emissions budgets.

XVI. Non-Federal Projects

A. Description of Final Rule

    EPA is amending Sec.  93.121(a) of the conformity rule so that 
regionally significant non-federal projects can no longer be advanced 
during a conformity lapse unless they have received all necessary state 
and local approvals prior to the lapse. Non-federal projects are 
projects that are funded or approved by a recipient of federal funds 
designated under title 23 U.S.C. or the Federal Transit Laws, but that 
do not require any FHWA/FTA funding or approvals. Under this final 
rule, recipients of federal funds cannot adopt or approve a regionally 
significant, non-federal project unless it is included in a currently 
conforming plan and TIP or is reflected in the regional emissions 
analysis supporting a currently conforming plan and TIP. The definition 
of non-federal project ``approval'' should be decided on an area-
specific basis through the interagency consultation process, and should 
be formalized in the area's conformity SIP. For more information on how 
areas have defined the point of final approval for a regionally 
significant non-federal project, see EPA's June 30, 2003 proposed rule 
(68 FR 38984), which is consistent with EPA's May 14, 1999 guidance 
that implements the court decision.

B. Rationale and Response to Comments

    In its ruling, the court found Sec.  93.121(a)(1) of the 1997 
conformity rule to be in violation of Clean Air Act section 
176(c)(2)(C). This provision of the 1997 rule had allowed state or 
local approval of transportation projects in the absence of a currently 
conforming plan and TIP. The court found that the Clean Air Act 
requires all non-exempt projects subject to the conformity rule, 
including regionally significant non-federal projects, to come from a 
conforming plan and TIP (or included in their supporting regional 
emissions analysis) to be funded or approved. However, the court also 
noted that once

[[Page 40048]]

a non-federal project receives all appropriate state or local 
approvals, it need not meet any further conformity requirements.
    Commenters generally concurred with EPA's proposed amendments to 
Sec.  93.121(a) as being consistent with the court decision. One 
commenter stated that it is reasonable to treat federal and regionally 
significant non-federal projects in like manner so that neither type of 
project can proceed during a lapse, as required by the court. Another 
commenter also agreed that the definition of non-federal project 
``approval'' should be determined through the interagency consultation 
process.
    One commenter, however, requested that EPA clarify the required 
approach for approving non-federal projects in isolated rural areas. As 
stated in the June 30, 2003 proposal, the conformity rule only applies 
to non-federal projects that are considered regionally significant, in 
that these projects must be included in a conforming transportation 
plan and TIP and/or the regional emissions analysis supporting a 
conforming plan and TIP. Isolated rural areas, however, are not 
required to develop metropolitan transportation plans and TIPs and are 
not subject to the conformity frequency requirements for plans and TIPs 
in Sec.  93.104 (including the 3-year conformity update requirement). A 
conformity determination in isolated rural areas is required only when 
a new non-exempt project needs federal funding or approval. Therefore, 
the commenter regarded the proposed rule as being unclear about whether 
isolated rural areas would need to conduct a separate conformity 
analysis that includes a new non-federal project before such a project 
could be funded or approved.
    EPA refers this commenter to Sec.  93.121(b) of the current 
conformity rule that includes the requirements for regionally 
significant non-federal projects in isolated rural nonattainment and 
maintenance areas. Section 93.121(b) states that no recipient of 
federal funds can approve or fund a regionally significant highway or 
transit project in an isolated rural area, regardless of funding 
source, unless: (1) The project was included in the regional emissions 
analysis supporting the most recent conformity determination; or (2) A 
new regional emissions analysis including the project and all other 
regionally significant projects expected in the isolated rural 
nonattainment or maintenance area demonstrates conformity. Such 
regional emissions analyses in isolated rural areas would include those 
projects in the statewide transportation plan and statewide TIP, 
including any existing or planned federal and regionally significant 
non-federal projects, that are in the nonattainment or maintenance 
area.
    Although EPA has always believed that the Clean Air Act does not 
require project-level conformity determinations for regionally 
significant non-federal projects, the Clean Air Act does require such 
projects to be included in the regional emissions analysis supporting a 
conformity determination before funding or approval can be given. See 
the January 11, 1993 proposal to the November 24, 1993 conformity rule 
for further background (58 FR 3772-3773). Recognizing that isolated 
rural areas do not have transportation plans and TIPs, in the preamble 
to the November 24, 1993 conformity rule (58 FR 62208) EPA states: ``In 
isolated rural areas, non-federal projects may be considered to have 
been included in a regional emissions analysis of the transportation 
plan and TIP if they are grouped with federal projects in the 
nonattainment or maintenance area in the statewide plan and STIP for 
the purposes of a regional emissions analysis.'' Therefore, we would 
consider the statute's conformity requirements to be satisfied in an 
isolated rural area if a regionally significant non-federal project is 
included in the area's previous regional emissions analysis and 
conformity determination (provided the project's design concept and 
scope have not changed significantly since the analysis and 
determination were made). If the project was not included in the 
previous regional emissions analysis and conformity determination, a 
new regional emissions analysis including the project must be 
completed.

XVII. Conformity Consequences of Certain SIP Disapprovals

A. Description of Final Rule

    Consistent with the June 30, 2003 proposal, this final rule changes 
the point in time at which conformity consequences apply when EPA 
disapproves a control strategy SIP without a protective finding. 
Specifically, the final rule deletes the 120-day grace period from 
Sec.  93.120(a)(2) of the 1997 conformity rule, so that a conformity 
``freeze'' occurs immediately upon the effective date of EPA's final 
disapproval of a SIP and its budgets that does not include a protective 
finding. A conformity freeze means that only projects in the first 
three years of the transportation plan and TIP can proceed. During a 
freeze, no new plans, TIPs or plan/TIP amendments can be found to 
conform until a new control strategy SIP fulfilling the same Clean Air 
Act requirement as that which EPA disapproved is submitted, and EPA 
finds the budgets in that SIP adequate for conformity purposes.
    In cases where EPA does not first make an affirmative adequacy 
finding for a new control strategy revision that is submitted to 
address a disapproved SIP, EPA is also clarifying in Sec.  93.120(a)(2) 
of today's rule that no new plans, TIPs or plan/TIP amendments can be 
found to conform during a freeze until EPA approves the submitted SIP 
revision. EPA is adding this clarification to Sec.  93.120(a)(2) to 
address the situation when EPA conducts its adequacy review through the 
SIP approval process. This clarification was not included in the June 
30, 2003 proposal; however, EPA does not believe that a reproposal is 
necessary to incorporate this minor revision in today's final rule. 
This minor revision simply clarifies how the conformity process 
currently operates in practice and is a logical outgrowth of the June 
2003 proposal that described how EPA can determine adequacy through the 
SIP approval process because such approval actions include a finding 
that a submitted SIP is adequate. See Section XV.C. above for more 
information on adequacy reviews that are conducted through the SIP 
approval process.
    EPA will not issue a protective finding for our disapproval of a 
submitted control strategy SIP (e.g., reasonable further progress and 
attainment SIPs) if the SIP does not contain enough emission reduction 
measures, or commitments to such measures, to achieve its specific 
purpose of either demonstrating reasonable further progress or 
attainment. If EPA disapproves a SIP without giving it a protective 
finding, the budgets cannot be used for conformity upon the effective 
date of EPA's disapproval action. See the June 30, 2003 proposal for 
more information on issuing a protective finding when EPA disapproves a 
control strategy SIP.
    Today's final rule does not impact the 1997 conformity rule's 
provisions for a SIP disapproval with a protective finding under Sec.  
93.120. This final rule also does not affect the 1997 conformity rule's 
flexibility that aligned conformity lapses with Clean Air Act highway 
sanctions (Sec.  93.120(a)(1)). Today's rule affects only the timing of 
conformity freezes for SIP disapprovals without a protective finding.

B. Rationale and Response to Comments

    In its ruling, the court found the 120-day grace period provided by

[[Page 40049]]

Sec.  93.120(a)(2) of the 1997 rule to be in violation of Clean Air Act 
section 176(c)(1) and remanded it to EPA for further rulemaking. 
Specifically, the court said that where EPA disapproves a SIP without a 
protective finding there is no basis to believe that conformity of 
transportation plans and TIPs to the submitted budget in the 
disapproved SIP will not cause or contribute to new violations, 
increase the frequency or severity of existing violations, or delay 
timely attainment of the air quality standards.
    Under Sec.  93.120(a)(2) of the 1997 rule, if EPA disapproved a 
submitted SIP or SIP revision without a protective finding, areas could 
use the 120-day grace period to complete a conformity determination 
that was already in progress. The court ruled that this grace period 
was not authorized by the statute because it would allow conformity to 
be demonstrated to a SIP that was determined not to be protective of 
the air quality standards. Therefore, we are eliminating the 120-day 
grace period from the conformity rule.
    Most comments on this rule revision supported the June 30, 2003 
proposal. One commenter specifically stated that this change will 
clarify time periods and eliminate confusion regarding the conformity 
requirements when a SIP is disapproved. One commenter, however, did not 
fully agree with EPA's proposal. This commenter argued that the 
proposed revision to Sec.  93.120(a)(2) still allows budgets to be used 
for some period after EPA disapproves a SIP without a protective 
finding, since such budgets could still be used in a conformity 
determination until the disapproval action becomes effective. The 
commenter objected to any rule that would allow budgets to be given 
effect for conformity purposes when the disapproved SIP and budgets are 
not consistent with reasonable further progress, attainment or 
maintenance.
    EPA agrees that SIPs and budgets that are inconsistent with Clean 
Air Act requirements for reasonable further progress, attainment or 
maintenance, should not be used in future conformity determinations. 
However, EPA also believes that a specific point in the SIP disapproval 
process at which budgets become ``disapproved'' and unavailable for 
conformity purposes needs to be established to provide certainty and 
consistency between the conformity and SIP processes. In this final 
rule we are establishing that point in the process as the effective 
date of EPA's SIP disapproval action. EPA has linked the immediate 
conformity consequences of a SIP disapproval without a protective 
finding to the effective date of that action to be consistent with an 
August 4, 1994 rulemaking that established the timing and 
implementation of offset and highway sanctions following certain SIP 
failures under 40 CFR 52.31.\21\ Specifically, 40 CFR 52.31(d)(1) 
states that ``the date of the [SIP disapproval] finding shall be the 
effective date as defined in the final action triggering the sanctions 
clock.'' In the August 1994 rulemaking, EPA has already concluded as a 
legal matter that a SIP disapproval, and by extension any consequences 
(e.g., sanctions, conformity freeze, etc.) associated with that 
disapproval, do not take effect until the effective date of EPA's 
action in the Federal Register.
---------------------------------------------------------------------------

    \21\ See 59 FR 39859, ``Selection of sequence of mandatory 
sanctions for findings made pursuant to section 179 of the Clean Air 
Act''--final rule.
---------------------------------------------------------------------------

    When EPA disapproves a SIP, the effective date of that action is 
generally only 30-60 days after the Federal Register publication of the 
disapproval. EPA believes that the minimum 30-day period is mandated by 
Sec. Sec.  552(a)(1) and 553(d) of the Administrative Procedure Act. 
These provisions require the publication of actions that may adversely 
affect areas in the Federal Register to include a minimum 30-day 
effective date.
    EPA also notes that such SIP disapprovals have occurred on a very 
infrequent basis, as EPA has only disapproved SIPs without a protective 
finding in three instances since the 1997 conformity rule was 
promulgated. Furthermore, for a SIP to be used in a conformity 
determination prior to the effective date of its disapproval, EPA would 
have found the SIP budget adequate. Such findings that would provide 
for the use of a SIP in the conformity process prior to its disapproval 
would not be expected in all cases, especially if the SIP is so 
deficient as to ultimately be disapproved without a protective finding. 
Therefore, EPA believes the impact of this rule change will be limited 
and generally will not result in the use of disapproved budgets in the 
conformity process.
    The same commenter also argued that EPA's approval of SIPs that 
include enforceable commitments to adopt additional future control 
measures for rate-of-progress, attainment or maintenance purposes, does 
not meet Clean Air Act requirements for these specific SIPs. To address 
this issue, the commenter requested that EPA revise Sec.  93.120 so 
that submitted SIPs that rely on enforceable commitments to adopt 
unspecified control measures could no longer be approved by EPA. The 
commenter argued that only SIPs that include adopted enforceable 
measures per 40 CFR 51.281 or written commitments to adopt specific 
measures that have been conditionally approved pursuant to Clean Air 
Act section 110(k)(4) can be approved.
    EPA did not propose revisions to Sec.  93.120 that would prohibit 
the full approval of SIPs that include enforceable commitments in this 
rulemaking, and therefore, cannot amend the conformity regulation to 
address this comment in today's final rule. This rulemaking merely 
deletes the 120-day conformity grace period from Sec.  93.120(a)(2) in 
accordance with the court decision. Further, the conformity rule only 
provides requirements for finding budgets adequate and does not include 
any limitations on EPA's ability to approve SIPs.
    EPA also disagrees with the commenter's position that SIPs that 
rely on enforceable commitments cannot be fully approved for the same 
reasons stated in Section XV.F.2. of this final rule. Furthermore, EPA 
does not believe the conformity regulations are the appropriate vehicle 
for specifying the criteria for approving SIP submissions. A more 
comprehensive response to this comment, including EPA's rationale, is 
included in the complete response to comments document in the public 
docket for this final rule. For information on how to access materials 
in the docket, see Section I.B. of this action.

XVIII. Safety Margins

A. Description of Final Rule

    As proposed, EPA is deleting Sec.  93.124(b) of the conformity rule 
that provided a narrowly targeted flexibility to areas with SIPs that 
had been submitted prior to the publication date of the original 
November 24, 1993 conformity rule. Under this provision, if an approved 
SIP submitted before November 24, 1993, had included a safety margin, 
but did not specify how the safety margin was to be used, an area could 
submit a revision to the SIP and specifically allocate all or a portion 
of the safety margin to the SIP's motor vehicle emissions budget(s). 
The 1997 rule allowed this SIP revision to become effective for 
conformity purposes before the revision had been approved by EPA. EPA 
is not aware of any nonattainment or maintenance areas that are 
currently affected by the elimination of this provision.

B. Rationale and Response to Comments

    The court decision found that Sec.  93.124(b) violated the Clean 
Air Act because it allowed a submitted but

[[Page 40050]]

unapproved SIP revision to supersede an approved SIP. The court ruled 
that EPA must fully approve these safety margin allocations into the 
SIP before they can be used for conformity, regardless of whether the 
SIP revision and safety margin was submitted before or after our 
November 1993 conformity rule.
    Although the court eliminated Sec.  93.124(b) for the use of safety 
margins in previously approved SIPs, the majority of areas that had 
allocated safety margins to their budgets after November 24, 1993, were 
not affected by the court's ruling. In general, areas that do not have 
approved SIPs can use submitted safety margins in conformity 
determinations once EPA finds the submitted SIP (and safety margin) 
adequate. Areas with approved SIPs that want to reallocate their safety 
margin for conformity purposes can do so once EPA has approved a SIP 
revision that specifically allocates all or a portion of the safety 
margin to a budget. Presently, no area is affected by the court's 
ruling, since SIP submissions with safety margins have either been 
approved by EPA or did not revise a previously approved SIP.
    EPA received three comments on the elimination of this provision 
based on the court's decision. Two commenters supported EPA's proposal 
and highlighted the potential relationship between the allocation of a 
safety margin and an area's ability to allow for growth in emissions 
from other source categories. One of these commenters specifically 
requested clarification on the benefits and impacts of assigning safety 
margins to motor vehicle emissions budgets. EPA agrees that the 
allocation of a safety margin to an area's budget can be an effective 
means to facilitate future conformity determinations. However, EPA 
notes that the allocation of a safety margin to the on-road 
transportation sector could impact an area's ability to allow growth in 
emissions from other source sectors (e.g., stationary sources). State 
and local transportation and air quality agencies and other affected 
parties should always consult on whether a safety margin is appropriate 
for conformity in a given area.
    Another commenter requested that the conformity rule be amended to 
require that maintenance areas demonstrate that Prevention of 
Significant Deterioration (PSD) increments will not be exceeded if the 
area allocates a safety margin that would allow on-road motor vehicle 
emissions to grow up to the level that is consistent with attainment 
for the area. This comment is relevant only to NO2 and 
PM10 maintenance areas, as EPA has not established PSD 
increments for carbon monoxide or ozone precursors. EPA has also 
established increments for sulfur dioxide (SO2); however, 
transportation conformity does not apply in SO2 
nonattainment and maintenance areas because on-road motor vehicles are 
not significant contributors to SO2 air quality problems in 
these areas.
    EPA does not agree that the transportation conformity rule needs to 
be amended to address this comment. Rather, EPA believes that the Clean 
Air Act and existing guidance and regulations are sufficient to prevent 
PM10 and NO2 maintenance areas from exceeding the 
amount of PM10 or NO2 increment that is available 
when these areas allocated safety margins to their budgets and 
NO2 and/or PM10 increments have been triggered. 
First, section 175A of the Clean Air Act requires that an area's 
maintenance plan must demonstrate that the area can maintain the 
relevant air quality standard for a period of 10 years. According to 
EPA's ``General Preamble for the Implementation of Title I of the Clean 
Air Act Amendments of 1990'' the maintenance plan must either 
demonstrate that future emissions will not exceed emissions that 
existed at the time that the request for redesignation was made or 
conduct a modeling analysis that shows the future mix of sources, 
emissions rates and control strategies for the area will not result in 
any violations of the air quality standard. At a minimum, areas should 
provide for some growth in stationary source emissions in their 
maintenance plans, where applicable. Therefore, any safety margin 
available would be emissions over and above the total amount of 
expected emissions, including growth in sources affected by PSD 
requirements.
    Second, the PSD program provides an opportunity for the permit 
applicant and the state to consult on how to address the allocation of 
a safety margin to the budgets while the PSD permit application is 
being prepared. Such consultation between the state and the potential 
source of NO2 or PM10 emissions helps to ensure 
that maintenance of the relevant national ambient air quality 
standard(s) is still achieved. Safety margins are expressed as a tons 
per day emissions rate for the entire nonattainment or maintenance 
area. PSD increments are expressed as a concentration of the pollutant 
in the ambient air (e.g., [mu]g/m3) in the area impacted by 
the emissions from the stationary source. States are encouraged to 
evaluate periodically whether an increment is available to be used by 
sources that are or will be applying for a PSD permit. If a state 
identifies a potential problem, the state could take timely action to 
address the problem. EPA's guidance \22\ indicates that a source which 
is applying for a PSD permit should consult with state and local 
agencies to determine the parameters that should be used to model 
emissions from on-road sources in the area that will be impacted by 
emissions from the source. During the course of this consultation, the 
state or local air agency should advise the applicant on how to 
properly account for on-road motor vehicle emissions in the area 
including the use of any portion of a safety margin that has been 
established for conformity in the SIP. In the event that a permit 
applicant encounters difficulty in satisfying the requirements for an 
increment analysis, the air quality agency would have the option of 
appropriately revising its SIP to allow the source to receive a PSD 
permit and adjust the safety margin allocation, if necessary. Finally, 
EPA notes that neither the Clean Air Act nor EPA's regulations and 
guidance require areas to assess increment consumption in connection 
with conformity determinations; this assessment is conducted only in 
connection with PSD permitting and periodic updates.
---------------------------------------------------------------------------

    \22\ NSR Workshop Manual PSD and Nonattainment Area Permitting--
Draft, October 1990, page C. 36.
---------------------------------------------------------------------------

XIX. Streamlining the Frequency of Conformity Determinations

A. Description of Final Rule

    EPA is finalizing several revisions to the frequency requirements 
listed in Sec.  93.104 of the conformity rule, consistent with the June 
30, 2003 proposal. Specifically, we are eliminating Sec.  93.104(c)(4) 
that required an MPO and DOT to determine conformity of the TIP within 
six months of the date that DOT determined conformity of the 
transportation plan. As a result of this rule revision, a TIP 
conformity determination will no longer be triggered upon DOT's 
conformity determination for the transportation plan. A conformity 
determination for the TIP will only be required when it is updated or 
amended, in accordance with Sec.  93.104(c)(1) and (c)(2). In addition, 
a conformity determination and new regional emissions analysis for the 
TIP will be required no less frequently than every three years, per 
Sec.  93.104(c)(3).
    EPA is also finalizing several rule revisions to streamline Sec.  
93.104(e) of the rule. In particular, we are eliminating Sec.  
93.104(e)(1) that required all

[[Page 40051]]

nonattainment and maintenance areas to determine conformity within 18 
months of November 24, 1993 (i.e., the date that EPA originally 
promulgated the conformity rule, 58 FR 62188). At this point in time, 
Sec.  93.104(e)(1) is no longer relevant for any area, and therefore, 
we are removing it from the rule.
    In addition, EPA is finalizing two revisions to Sec.  93.104(e)(3), 
which requires a conformity determination within 18 months of EPA's 
approval of a SIP. First, we are specifying that this 18-month clock 
begins on the effective date of EPA's approval of the SIP. This 
clarification will resolve any ambiguity in the current rule as to when 
this 18-month clock begins.
    The second revision to Sec.  93.104(e)(3) will require a conformity 
determination only when a conformity determination has not already been 
made using that same budget in the newly-approved SIP. That is, if an 
area determined conformity using adequate budgets from a submitted SIP, 
and those budgets had not changed before EPA subsequently approves the 
submitted SIP, then the area would not have to redetermine conformity 
within 18 months of EPA's approval of the SIP. EPA believes that if 
approved budgets have already been used in a conformity determination, 
there is no added environmental benefit in requiring another conformity 
determination to be made within 18 months of EPA's approval of a SIP 
that contains these same budgets. EPA notes that budgets are unchanged 
if they are for the same pollutant or precursor, the same quantity of 
emissions, and the same year.
    EPA is also eliminating Sec.  93.104(e)(4), which required a 
conformity determination to be made within 18 months of EPA's approval 
of a SIP that adds, deletes, or changes a TCM. As stated in the June 
30, 2003 proposal to this final rule, EPA believes that this 
requirement is redundant with the requirements in Sec. Sec.  
93.104(e)(2) and (3) relating to conformity determinations after other 
SIP approvals, and therefore, is unnecessary.
    Finally, EPA is making two changes to Sec.  93.104(e)(5), which 
requires a new conformity determination within 18 months of EPA's 
promulgation of a federal implementation plan (FIP). First, the final 
rule indicates that the clock for this requirement also starts on the 
effective date of EPA's promulgation of a FIP to be consistent with the 
start date of the other SIP triggers found in Sec.  93.104(e). Second, 
EPA is deleting the phrase ``or adds, deletes, or changes TCMs,'' for 
the same reasons that we are deleting Sec.  93.104(e)(4) discussed 
above. EPA believes that the purpose of Sec.  93.104(e)(5) will be 
adequately served by the requirement to show conformity after EPA 
promulgates a FIP containing a budget.

B. Rationale and Response to Comments

    In the first conformity rule proposal published in January 1993, we 
stated, ``EPA believes conformity determinations should be made 
frequently enough to ensure that the conformity process is meaningful. 
At the same time, EPA believes it is important to limit the number of 
triggers for conformity determinations in order to preserve the 
stability of the transportation planning process'' (58 FR 3775). As a 
result of these dual goals and based on experience gained through 
implementing the conformity rule to date, we are eliminating some of 
the frequency requirements found in Sec.  93.104, and streamlining 
others. EPA believes that this final rule will simplify the current 
conformity requirements without compromising the environmental benefits 
of the conformity program.
    Under today's rule, EPA concludes that conformity determinations 
will continue to be required frequently enough to ensure that the 
process is meaningful and consistent with the Clean Air Act. In this 
final rule, we have not made any changes to the requirement that new or 
revised plans, TIPs and projects must demonstrate conformity before 
they can be funded or approved. Furthermore, the final rule retains the 
requirement to determine conformity of transportation plans and TIPs at 
least every three years, as required by section 176(c) of the Clean Air 
Act. We are eliminating only those frequency requirements that are not 
expressly required by the Clean Air Act and that we now believe are 
either outdated or redundant with other requirements.
    In general, commenters supported EPA's proposals to streamline the 
conformity frequency requirements. Most commenters agreed that these 
changes would improve the conformity rule and would serve to avoid 
confusion and simplify the overall conformity process. In addition, 
some commenters believed that these rule changes would reduce the 
number of required conformity determinations, and therefore, would 
conserve limited planning resources.
    One commenter, however, opposed the elimination of the 6-month TIP 
clock in Sec.  93.104(c)(4), stating that this rule change would result 
in MPOs having always to demonstrate conformity of the plan and TIP at 
the same time. This commenter believed that by eliminating the 6-month 
TIP clock, MPOs will lose the extra time and flexibility provided by 
the Sec.  93.104(c)(4) provision that may be needed to update the TIP 
and demonstrate conformity after a conformity determination for the 
plan has been made.
    EPA does not believe that the elimination of Sec.  93.104(c)(4) and 
the 6-month TIP clock will result in the loss of time or flexibility 
for MPOs as this commenter has suggested. In contrast, EPA believes 
that this rule change will result in greater flexibility and less 
demands on planning resources to meet the conformity requirements.
    As stated in the June 30, 2003 proposal, EPA believes that Sec.  
93.104(c)(4) is unnecessary because of other conformity and planning 
requirements that are in place. Therefore, the rule change will have no 
practical effect on the conformity process in most cases. According to 
the transportation planning statute (23 U.S.C. 134(h)(3)(C)), projects 
in the TIP must be consistent with the transportation plan to be 
federally funded or approved. Therefore, in cases where a plan is 
changed and a conformity determination is made, areas will continue to 
ensure that their TIPs also conform and are consistent with the plan to 
advance projects, regardless of whether the 6-month TIP trigger is part 
of the conformity regulation. If a plan changes in years also covered 
by the TIP, then the TIP would also be updated or amended to meet the 
planning regulations at the same time. Under today's final rule, 
conformity determinations will continue to be required for such plan 
and TIP changes. However, EPA's final rule and DOT's planning 
regulations would not require a TIP revision and conformity 
determination in the case where a plan is changed in a manner that does 
not affect the TIP.
    Another commenter requested EPA to remove all TIP references and 
actions from the conformity rule, since the TIP is required to be 
consistent with a conforming transportation plan. The commenter 
believed that DOT's planning regulations and their originating 
legislation make EPA's TIP requirements and actions redundant and 
unnecessary, and that the removal of such requirements would improve 
the conformity rule.
    EPA did not propose the removal of all TIP references and 
conformity requirements in this rulemaking, and therefore, cannot 
address the commenter's request in this final rule. Furthermore, EPA 
believes the current references and conformity requirements for TIPs 
are necessary to be consistent

[[Page 40052]]

with the Clean Air Act. The current Clean Air Act section 176(c)(2)(A) 
specifically states that ``no transportation plan or transportation 
improvement program may be adopted* * *'' until such plans and programs 
are shown to demonstrate conformity. Therefore, EPA believes that the 
corresponding regulations must reflect the statutory requirements for 
both the transportation plan and TIP.

XX. Latest Planning Assumptions

A. Change to Latest Planning Assumptions Requirement

1. Description of Final Rule
    EPA is amending Sec.  93.110(a) to change the point in the 
conformity process when the latest planning assumptions are determined. 
This final rule will allow conformity determinations to be based on the 
latest planning assumptions that are available at the time the 
conformity analysis begins, rather than at the time of DOT's conformity 
determination for a transportation plan, TIP, or project. Under today's 
final rule, the interagency consultation process should be used to 
determine the ``time the conformity analysis begins'' as described in 
B.1. and C.1 of this section.
2. Rationale and Response to Comments
    EPA believes that today's final rule will make the conformity rule 
more workable for implementers while continuing to meet the basic Clean 
Air Act requirement that the latest planning assumptions be used in 
conformity determinations. Most commenters agreed and strongly 
supported EPA's proposed change to the latest planning assumptions 
requirement. Some of these commenters noted that the proposed changes 
to Sec.  93.110(a) would provide more certainty to the process and 
conserve valuable state and local resources.
    A few commenters, however, did not agree with EPA's proposed 
change. One commenter argued that the proposed rule violates the Clean 
Air Act by allowing conformity determinations to be based upon 
information other than ``the most recent population, employment, travel 
and congestion estimates.'' This same commenter also stated that the 
proposed change would undermine reasoned decision-making by making the 
most accurate and reliable information irrelevant since data developed 
after the time the analysis begins would not be required to be 
considered until the next conformity determination. Another commenter 
reiterated this concern by stating that the proposed rulemaking 
improperly locks-in the planning assumptions that exist at the start of 
the conformity determination process, even though the actual conformity 
determination is typically made months later when more recent 
information could be available.
    EPA disagrees that today's proposal is inconsistent with the Clean 
Air Act. Section 176(c)(1) of the Clean Air Act requires conformity 
determinations to be based on the most recent data and emissions 
estimates that are available. However, the Clean Air Act does not 
explicitly define the point in the conformity process when the most 
recent estimates should be determined. Therefore, EPA believes that 
this ambiguity in the Clean Air Act allows for a procedural change in 
how the latest planning assumptions requirement is implemented.
    As stated in the proposal to this final rule, when EPA originally 
wrote the conformity rule in 1993, we did not fully envision how the 
requirement for the use of latest planning assumptions would be 
implemented in practice. Under the previous conformity rule, if an MPO 
had completed a regional emissions analysis for its plan and TIP 
conformity determinations, and new information became available as late 
as the day before DOT was scheduled to make its conformity 
determination, DOT was not able to complete its action, as the MPO 
would have had to revise the conformity analysis to incorporate the new 
data. EPA does not believe this situation is appropriate or consistent 
with the overall intent of the Clean Air Act to coordinate air quality 
and transportation planning.
    EPA also disagrees that the proposed rule revision would undermine 
decision-making and allow for the use of irrelevant information in the 
conformity process. Although EPA believes that conformity 
determinations should be based on the most recent data and planning 
information in accordance with the Clean Air Act, we also believe that 
the conformity rule should provide certainty in implementing the 
statute's requirements. In other words, EPA believes that a conformity 
determination that is based on the most recent information available 
when that analysis is conducted should be allowed to proceed even if 
more recent information becomes available later in the conformity 
process.
    EPA believes it can provide this certainty, without compromising 
air quality, due to the iterative nature of the conformity process. A 
conformity determination based on the latest planning assumptions and 
emissions models is required at a minimum of every three years. In 
addition, the conformity rule (40 CFR 93.104) requires a conformity 
determination for plan and TIP updates and amendments and within 18 
months of certain EPA SIP actions (e.g., when EPA finds an initially 
submitted SIP budget adequate). In the case where new data becomes 
available after an analysis has started, such information would be 
required in the next conformity determination to ensure that 
appropriate decisions concerning transportation and air quality are 
being made. Therefore, EPA does not believe this rule change will 
provide for the general use of ``irrelevant'' data in the conformity 
process. Rather, EPA believes this rule change will provide a 
reasonable approach to ensuring that conformity is based on accurate 
and available information without causing unnecessary delays late in 
the transportation planning process. EPA concludes that today's final 
rule is consistent with the Clean Air Act, as it provides a reasonable 
time at which latest planning assumptions are determined for use in a 
conformity determination.
    Two commenters also expressed concern about the proposed rule's 
potential to eliminate the public's involvement in the selection of 
latest planning assumptions used in conformity determinations. One of 
these commenters stated that the proposed rule change would defeat the 
ability of interested parties from playing a meaningful role in the 
decision-making process by making new information developed after 
public notice of the emissions analysis and conformity determination 
irrelevant. The other commenter requested clarification on the 
obligation of an MPO to revise a conformity determination to address 
public comment that questions an area's use of the most recent planning 
information in the conformity analysis.
    EPA does not believe that today's rule change will eliminate the 
public's involvement in selecting the latest planning assumptions that 
are used in conformity determinations. For proposed transportation 
plan/TIP updates, amendments and conformity determinations, the public 
has an opportunity to comment on whether the conformity determination 
meets the conformity rule's requirements for using the latest planning 
information. Under today's rule, the public will still have this 
opportunity, as the amendment to Sec.  93.110(a) makes no changes to 
the public involvement requirements under Sec.  93.105(e).
    EPA also does not believe that this rule change will effectively 
alter an MPO or other designated agency's

[[Page 40053]]

responsibility to respond to public comments in a manner consistent 
with the conformity rule's requirements. Under today's final rule, when 
an MPO or other designated agency conducts a conformity determination, 
it should document in its determination the ``time the conformity 
analysis begins'' as determined by interagency consultation, the date 
on which the analysis was started and the planning assumptions that 
were used. During the public process and comment period, the public 
will continue to have the opportunity to comment on all these aspects 
of the conformity analysis. If, for example, a member of the public 
expresses concern that planning information available before the 
beginning of the analysis was not used in the conformity determination, 
an MPO would have to address such concerns and explain why the 
information was not incorporated. If, when addressing this comment, the 
MPO and other interagency consultation partners determine that the 
information was available prior to the start date of the analysis, the 
MPO or other designated agency would be required to re-run its analysis 
to incorporate such data to meet the conformity rule's requirements.
    In contrast to those commenters who favored the previous rule's 
more stringent requirement, some commenters did not believe that the 
proposed change to Sec.  93.110(a) would provide enough flexibility in 
implementing the latest planning assumptions requirement. Specifically, 
these commenters requested that EPA amend the conformity rule to define 
the ``most recent planning assumptions available'' as those assumptions 
used to develop the most recent applicable SIP and motor vehicle 
emissions budget(s). Under the existing conformity rule, one commenter 
stated that the transportation sector can be unfairly forced to reduce 
emissions simply because planning assumptions have changed since the 
SIP was developed. Since the existing process can result in the use of 
different planning assumptions in SIPs and conformity, another 
commenter argued that the proposed rule still runs counter to 
Congressional intent and the Clean Air Act which is to provide for an 
integrated planning process. One commenter stated that both 
transportation and air quality agencies would benefit from using the 
same planning assumptions that were used for both conformity analyses 
and SIP development. Another commenter agreed with this approach, 
provided that the SIP was approved in the last five years.
    The final rule has not been changed from the June 30, 2003 proposal 
in response to these comments. In the 1993 conformity rule (58 FR 
62210), EPA stated that: ``It should be expected that conformity 
determinations will deviate from SIP assumptions regarding VMT, growth, 
demographics, trip generation, etc., because the conformity 
determinations are required by Clean Air Act section 176(c)(1) to use 
the most recent planning assumptions.'' For today's rulemaking, EPA did 
not propose to alter this aspect of Sec.  93.110 as determined in the 
original conformity rule. Although EPA agrees that Congress intended 
for the integration of transportation and air quality planning through 
the conformity process, EPA believes that Congress also clearly 
intended for conformity to be based on the most recent planning 
information even if it differs from the assumptions used to develop the 
SIP and regardless of how recently a SIP was developed. The purpose of 
conformity is to ensure that emissions projected from planned 
transportation activities are consistent with the emissions level 
established in the SIP. If new planning assumptions introduced into the 
transportation and conformity processes result in an increase or 
decrease in projected emissions, EPA believes it is the responsibility 
of transportation and air quality agencies, along with other 
interagency consultation partners, to determine how best to consider 
the anticipated emissions change. In cases where projected emissions 
increase over the applicable SIP budget(s), the consultation process 
would be used to consider a revision to the transportation plan and TIP 
and/or the SIP to ensure that a conformity determination can be made 
and an area's air quality goals are achieved.

B. Defining the Time the Conformity Analysis Begins

1. Description of Final Rule
    In the June 30, 2003 proposal, EPA requested comment on how MPOs, 
state departments of transportation, transit agencies, and air quality 
agencies would define the ``time the conformity analysis begins.'' 
Based on the comments received, EPA is finalizing our proposed 
clarification for the start of the regional conformity analysis in 
Sec.  93.110(a) of today's final rule. Specifically, the final rule 
clarifies the time the conformity analysis begins as the point at which 
the MPO or other designated agency begins to model the impact of the 
proposed transportation plan, TIP or project on VMT and speeds and/or 
emissions for a conformity determination. This point should be 
determined through interagency consultation and used consistently for 
all future conformity determinations.
    For example, the beginning of the analysis for a transportation 
plan or TIP conformity determination might be the point at which travel 
demand modeling begins to generate the VMT and speed data that will be 
used to calculate emissions estimates for the conformity determination. 
For smaller MPOs and rural areas that do not use a travel demand model, 
the beginning of the conformity analysis might be the point at which 
VMT projections necessary to run the emissions model are calculated 
based on the most recent Highway Performance Monitoring System (HPMS), 
population and employment data that are available at that time.
    EPA does not, however, intend for the beginning of the analysis 
that will support a transportation plan or TIP conformity determination 
to be before VMT and emissions estimates have begun to be calculated. 
The following examples illustrate when the analysis has not yet begun:
     When the initial list of projects for the plan and TIP 
have been developed or before those projects have been coded into the 
transportation network;
     If travel or emissions modeling is conducted to 
preliminarily examine the impact of several potential projects or 
project alternatives on travel or emissions in the area; or
     When an initial schedule for completing an analysis is 
developed during an interagency consultation meeting.

Whatever the case, any information and assumptions that become 
available before actual modeling for a conformity determination has 
commenced would be required to be considered in that conformity 
determination.
2. Rationale and Response to Comments
    EPA received a number of comments with suggestions for defining the 
time the conformity analysis begins. After thorough consideration of 
these comments, EPA believes this final rule adequately describes our 
intentions for what criteria constitute the time the analysis 
``begins.''
    Other suggested approaches that we received included defining the 
beginning of the analysis as the date on which state and local agencies 
submit their projects to be included in the plan and TIP; the point 
where model parameters and inputs have been incorporated into the 
travel demand model; and, the time at which a project is adopted for 
inclusion into a plan or TIP. EPA did not believe that these

[[Page 40054]]

suggestions were consistent with our intentions of having the start of 
the analysis represent a point in the process when actual modeling of 
the travel or emissions impacts of the planned transportation system on 
air quality has begun, since these activities can occur some time 
before modeling for the conformity determination occurs. EPA believes 
that all new planning assumptions available at the time the actual 
travel or emissions modeling begins, could be incorporated in a 
conformity determination, and therefore, it would be unreasonable to 
not require such data to be used.
    One commenter suggested that the time the analysis begins should be 
necessarily after the interagency consultation process has been 
completed. EPA believes this approach for defining the start of the 
analysis could lead to confusion and is also inconsistent with our 
proposal, as the completion of the interagency consultation process 
could represent a point in time well after travel and/or emissions 
modeling have begun (e.g., the point in time when the conformity 
determination is made).
    Another commenter also suggested that determining the start of the 
analysis be the prerogative of the MPO, rather than determined through 
interagency consultation. EPA disagrees. EPA believes having the start 
of the analysis determined through interagency consultation is critical 
for ensuring that transportation and air quality planners work together 
to meet air quality goals. Several commenters also agreed that using 
the interagency consultation process to decide this issue is 
appropriate, as further discussed in C.2 of this section).
    A few commenters requested that EPA provide further guidance in the 
final rule for defining the beginning of the analysis, as they 
interpreted the proposal to be ambiguous and the source of unintended 
consequences. EPA agrees with these commenters, and therefore, has 
defined the start of the conformity analysis in Sec.  93.110(a) of 
today's rule based on concepts described in the preamble to the 
proposed rule. In addition, EPA has provided further explanation and 
examples in the description of this final rule of what we intend the 
beginning of the conformity analysis to be.

C. Implementation of Final Rule

1. Description of Final Rule
    Today's final rule relies on the interagency consultation process 
required by Sec.  93.105(c)(1)(i) to determine when a conformity 
analysis reasonably begins in a given area. Section 93.105(c)(1)(i) 
already requires the consultation process to be used to decide which 
planning assumptions and models are available for use by the MPO or 
other designated agencies responsible for conducting conformity 
analyses. The definition of when the conformity analysis begins for a 
given area should be well documented through the interagency 
consultation process. New information (e.g., population or fleet data) 
that becomes available after the conformity analysis begins is not 
required to be incorporated into the current analysis if the analysis 
is on schedule, although an area could voluntarily include the new 
information at any time as appropriate. EPA encourages the MPO or other 
designated agency to use the interagency consultation process to inform 
other involved agencies of when a conformity emissions analysis has 
started for a given conformity determination.
    To support a valid conformity determination, the MPO or other 
appropriate agency should also document the following information:
     How the ``time the conformity analysis begins'' has been 
defined through interagency consultation;
     The calendar date that the conformity analysis began; and,
     The planning assumptions used in the analysis.

Documenting this information in the actual conformity determination 
would inform the public of previous decisions regarding the use of 
latest planning assumptions, and will record when an analysis was 
begun, so that commenters can address any issues related to these 
decisions.
    Today's final rule also clarifies that new data that becomes 
available after a conformity analysis has started is required to be 
used in the upcoming current conformity determination if a significant 
delay in the analysis has occurred before a substantial amount of work 
has been completed. For example, an MPO starts a conformity analysis 
and begins generating VMT estimates from the travel demand model. 
However, the MPO's analysis is then delayed for six months. In this 
case, EPA believes it is reasonable to expect that an MPO should 
incorporate new planning information that became available during the 
six-month delay period. Under today's final rule, the interagency 
consultation process would be used to determine whether a significant 
delay has occurred and whether new data that becomes available during a 
delay should be incorporated.
    EPA intends that in cases where areas adhere to their conformity 
determination schedules and such delays do not occur, the incorporation 
of new information that becomes available after the conformity analysis 
has begun is not required. The final rule only requires the 
incorporation of new information when an area falls significantly 
behind in completing a conformity analysis, as determined through 
interagency consultation.
    Areas should consider the availability of new planning assumptions 
when determining their conformity schedules. The consultation process 
should continue to be used to determine what are the most recent 
assumptions available for SIP development, so that they can be 
incorporated into the conformity process expeditiously. For example, if 
EPA is expected to find a new SIP budget adequate before the MPO or 
DOT's conformity determination, conformity to the new SIP budget would 
be required. In such a case, transportation planners should use the 
more recent assumptions in the submitted SIP and consider them at the 
start of the conformity analysis, since the more recent assumptions 
would have been available through the consultation process when the SIP 
was being developed. State and local air agencies should continue to 
inform their transportation counterparts of new assumptions as they 
become available.
    This final rule addresses only when latest planning assumptions 
must be considered and does not change the requirement that DOT's 
conformity determination of the transportation plan and TIP must be 
based on an analysis that is consistent with the proposed 
transportation system. For example, if a regionally significant project 
is significantly changed after the start of the conformity analysis, 
such a change must be reflected in the conformity analysis for the 
current determination. Likewise, a significant change in the design 
concept and scope of an emissions reduction program would also have to 
be reflected before DOT makes its conformity determination.
    Today's proposal also does not change the requirements of Sec.  
93.122(a) which describes when emissions reduction credit can be taken 
in regional emissions analyses. Section 93.122(a)(2) continues to 
require that analyses reflect the latest information regarding the 
implementation of TCMs or other control measures in an approved SIP, 
even if a measure is cancelled or changed after the conformity analysis 
begins. In addition, Sec.  93.122(a)(3) continues to require that DOT's 
conformity determination be made only when regulatory control programs 
have been assured and will be implemented

[[Page 40055]]

as described in the SIP. However, consistent with the rule change on 
availability of latest planning assumptions, today's rule allows areas 
to rely upon the latest existing information as documented at the 
beginning of the conformity analysis regarding the effectiveness of SIP 
control programs that are being implemented as described in the SIP 
(Sec.  93.110(e)).
    Finally, Sec.  93.122(a)(6) is similarly not amended by today's 
action. The conformity rule continues to require that the conformity 
analysis be based on the same ambient temperature and other applicable 
factors used to establish the SIP's motor vehicle emissions budget.
2. Rationale and Response to Comments
    Many commenters agreed that the interagency consultation process 
should be central in determining the beginning of the conformity 
analysis. Given the unique circumstances of individual areas, some 
commenters believed that the interagency consultation process would 
provide a common sense approach to implementing the proposed Sec.  
93.110(a). One commenter also believed that EPA's approach for relying 
on interagency consultation for determining if an analysis is delayed 
and whether more recent data should be used is appropriate. This 
commenter argued that such an approach would provide for greater 
flexibility and local decisionmaking. EPA agrees with these comments to 
use the interagency consultation process to account for differences in 
the planning and conformity processes among individual nonattainment 
and maintenance areas.
    One commenter, however, expressed concern over EPA's proposal to 
require the use of more recent data that has become available if an 
analysis is delayed. The commenter stated that this proposal lacked 
specificity and could potentially nullify the proposed flexibility 
provided by the revised Sec.  93.110(a).
    EPA believes that in cases where a significant delay in the start 
of the analysis has occurred and more recent data becomes available 
during that time, the new data must be included in the conformity 
determination. In response to this comment, EPA has clarified in the 
final rule that new data that becomes available after an analysis has 
begun is required to be used in the upcoming conformity determination 
if a significant delay in the analysis has occurred. As described 
above, EPA has provided further explanation and examples to more fully 
depict our intentions for this requirement in the description of this 
final rule. Interagency consultation would be used, following Section 
C.1. above, to decide whether a conformity analysis has been delayed 
and whether any new data has become available during the delay that 
would be incorporated into the conformity process.
    Another commenter requested that the final rule require an MPO to 
incorporate new planning assumptions that become available after an 
analysis has started, if changes to other aspects of a conformity 
determination (e.g., data, conclusions or assumptions) are made once 
the analysis has begun. In such cases, this commenter believed that the 
planning assumptions should again be reviewed, and if they have 
changed, such newer assumptions should be incorporated in the 
conformity determination along with any other changes the MPO is 
conducting.
    As previously stated, EPA believes that once a conformity analysis 
begins, it is appropriate to allow that analysis to continue without 
requiring the incorporation of newer planning information, provided the 
conformity analysis and determination remain on schedule, as determined 
through interagency consultation. EPA does not believe that new 
planning information should be required if changes to the conformity 
analysis are made that do not cause a significant delay. However, in 
this case, EPA encourages areas to consider incorporating new 
information that has become available since the analysis began if other 
changes are initiated and new data can also be easily incorporated.
    EPA believes it is appropriate to require the use of more recent 
planning assumptions that become available after a conformity analysis 
begins only if significant delays in completing the conformity analysis 
have occurred. Therefore, if an MPO or other designated agency 
initiates a change to the conformity analysis that causes a significant 
delay, EPA believes that any new planning information that has become 
available since the analysis began should be required in that 
conformity determination, as determined by the interagency consultation 
process.
    Finally, several commenters requested clarification on various 
aspects of implementing the use of latest planning assumptions in 
conformity. Specifically, one commenter requested EPA to indicate in 
the final rule what newer information that becomes available will be 
required in a conformity determination even after the latest planning 
assumptions have been agreed upon through interagency consultation. 
This commenter stated that the final rule should specify those 
assumptions to avoid ambiguity.
    EPA believes that Sec.  93.110 of the current conformity rule 
provides a detailed description of the latest planning assumptions that 
must be incorporated in a conformity determination. For example, Sec.  
93.110(b) states that assumptions must be derived from the most recent 
estimates of current and future population, employment, travel, and 
congestion. Sections 93.110(c) and (d) require using the latest 
planning information on transit fares, service levels and ridership, as 
well as road and bridge tolls. In addition, Sec.  93.110(e) specifies 
that conformity determinations must include the latest existing 
information regarding the effectiveness of transportation and other 
control measures that have been implemented. Under today's rule, an 
area's interagency consultation process would determine the most recent 
data and information available to meet Sec.  93.110 requirements at the 
beginning of the conformity analysis. Provided the analysis starts on 
time and adheres to the conformity determination schedule, any updates 
to this information would not be required to be used until the next 
conformity determination.
    However, this final rule does not change any other provision of the 
conformity rule. For example, this final rule does not change the 
requirement that DOT's conformity determination of the transportation 
plan and TIP be based on an analysis that is consistent with the 
proposed transportation system. In addition, the final rule does not 
change the existing requirements for determining regional 
transportation emissions under Sec.  93.122. For example, as described 
above, Sec.  93.122(a)(2) continues to require that analyses reflect 
the latest information regarding the implementation of TCMs or other 
control measures in an approved SIP, even if a measure is cancelled or 
changed after the beginning of the conformity analysis. EPA believes 
the requirements of both Sec. Sec.  93.110 and 93.122 are clear and 
provide sufficient direction to implement today's final rule, and 
therefore, EPA has not made any further clarifications to these 
requirements in response to this comment.
    Another commenter requested that EPA clarify in the final rule that 
MPOs may demonstrate conformity without being required to wait for 
changes in planning data that are not actually available. This 
commenter suggested that in some areas conformity determinations have 
been delayed to

[[Page 40056]]

incorporate anticipated data (e.g., new Census data) that was not 
actually available at the time the determination was originally 
scheduled to be made.
    The Clean Air Act and conformity rule do not require MPOs to delay 
their conformity analyses to incorporate anticipated data that is not 
yet available for conformity purposes under any circumstances. The 
conformity rule, as amended in today's action, only requires conformity 
determinations to incorporate the most recent planning information 
available at the time the conformity analysis begins. Under this final 
rule, areas should use the interagency consultation process to 
determine the start of the analysis and the planning assumptions that 
are available and will be used in that analysis.
    Two commenters asked for clarification on the requirements of Sec.  
93.122(a)(6) as they relate to planning information used in regional 
emissions analyses. Section 93.122(a)(6) requires regional emissions 
analyses to include the same ambient temperatures and other applicable 
factors that were used to develop the SIP and budgets. However, since 
Sec.  93.110 requires the use of the most recent planning assumptions 
available in conformity, one commenter requested clarification on the 
specific ``factors'' that Sec.  93.122(a)(6) targets. One of these 
commenters also requested clarification on whether this provision of 
the rule should be applied to project level hot-spot analyses. This 
commenter argued that localized data can be more accurate than regional 
estimates in some cases, and therefore, should be used in hot-spot 
analyses.
    In contrast to those planning assumptions described in Sec.  93.110 
(e.g., population, employment, vehicle fleet composition), EPA intended 
Sec.  93.122(a)(6) to apply to certain planning factors that would not 
be expected to change significantly over time in a given geographical 
area. For example, factors referred to in Sec.  93.122(a)(6) would 
include environmental conditions such as ambient temperatures, humidity 
and altitude. Other factors subject to Sec.  93.122(a)(6) could also 
include the fraction of travel in a hot stabilized engine mode and 
annual mileage accumulation rates over the time frame of the 
transportation plan. Since factors such as environmental conditions and 
certain vehicle use characteristics that do not typically change in 
future years could significantly impact emissions, EPA generally 
believes that it is appropriate to require such factors to be 
consistent between conformity analyses and the SIP budgets.
    Under certain circumstances, however, it may be appropriate to use 
alternative factors instead of certain SIP assumptions, if it is 
determined through the interagency consultation process that these 
factors should be modified as provided for in Sec.  93.122(a)(6). For 
example, such modifications in these types of factors may be 
appropriate where additional or more geographically specific 
information is incorporated or a logically estimated trend in such 
factors beyond the period considered in the SIP is represented. EPA 
does not expect changes in the SIP's factors to occur often, and they 
could occur only after interagency consultation. These factors, along 
with all other planning assumptions used in a conformity analysis, must 
be documented in the conformity determination that is released for 
public comment.
    Finally, Sec.  93.123(c)(3) of the conformity rule requires hot-
spot analysis assumptions to be consistent with those assumptions used 
in the regional emissions analysis for those inputs which are required 
for both analyses. Therefore, the requirements of Sec.  93.122(a)(6) 
also apply to hot-spot analyses; those factors covered by Sec.  
93.122(a)(6) used in regional emissions analyses generally need to be 
the same as those in hot-spot analyses. However, EPA believes the 
existing Sec.  93.122(a)(6) provides flexibility to use different 
information for certain environmental and transportation-related 
factors (e.g., temperature, cold-start vehicle travel) in hot-spot 
analyses, if it is determined through interagency consultation that 
there is a sound basis for using more localized geographic data. Areas 
should use the interagency consultation procedures established under 
Sec.  93.105 to determine whether more localized data is appropriate in 
hot-spot analyses.

XXI. Horizon Years for Hot-Spot Analyses

A. Description of the Final Rule

    Today's final rule clarifies Sec.  93.116 of the conformity rule so 
that project-level hot-spot analyses in metropolitan nonattainment and 
maintenance areas must consider the full time frame of an area's 
transportation plan at the time the analysis is conducted.\23\ Regional 
emissions analyses in isolated rural areas also cover a 20-year 
timeframe, consistent with the general requirements in metropolitan and 
donut areas. Alternatively, hot-spot analyses for new projects in 
isolated rural nonattainment and maintenance areas, as defined in 
today's rule, must consider the full time frame of the area's regional 
emissions analysis since these areas are not required to develop a 
transportation plan and TIP under DOT's statewide transportation 
planning regulations. All areas would use the interagency consultation 
process to select the specific methods and assumptions for conducting 
both quantitative and qualitative hot-spot analyses in accordance with 
Sec.  93.123 of the conformity rule (Sec.  93.105(c)(1)(i)).
---------------------------------------------------------------------------

    \23\ Under DOT's current planning regulation, transportation 
plans in metropolitan nonattainment and maintenance areas need to be 
updated every three years and cover at least a 20-year planning 
horizon (23 CFR 450.322(a)).
---------------------------------------------------------------------------

    EPA does not anticipate that today's clarification would 
significantly change how project-level analyses are being conducted in 
practice. To ensure that the requirement for hot-spot analysis is being 
satisfied, areas should examine the year(s) within the transportation 
plan or regional emissions analysis, as appropriate, during which peak 
emissions from the project are expected and a new violation or 
worsening of an existing violation would most likely occur due to the 
cumulative impacts of the project and background regional emissions in 
the project area. EPA believes that if areas demonstrate that no hot-
spot impacts occur in the year(s) of highest expected emissions, then 
they will have shown that no adverse impacts will occur in any years 
within the time frame of the plan (or regional emissions analysis).
    Today's final rule does not change the procedural requirements for 
hot-spot analyses outlined in Sec.  93.123, nor the flexibility for 
areas to decide how best to meet these requirements through interagency 
consultation. We believe our clarification to Sec.  93.116, in 
combination with the rule's existing consultation and modeling 
requirements, is sufficient to demonstrate that a project will not 
cause or contribute to new local violations or increase the severity of 
existing violations during the period of time covered by the 
transportation plan.

B. Rationale and Response to Comments

    On May 26, 1994, Environmental Defense, Natural Resource Defense 
Council and Sierra Club collectively submitted to EPA a Petition for 
Reconsideration of the November 1993 conformity rule (58 FR 62188). In 
the preamble to an April 10, 2000 conformity rule (65 FR 18913), we 
addressed four remaining issues raised in this petition, one of which 
was the issue regarding horizon years for hot-spot analyses. 
Specifically, the petitioners requested that we alter the rule to 
ensure that areas examine the 20-year time frame of the transportation

[[Page 40057]]

plan when conducting hot-spot analyses. The existing transportation 
conformity rule does not clearly specify a time frame to be considered 
for hot-spot analyses.
    In the preamble to the 2000 amendment, we acknowledged that hot-
spot analyses should address the full time frame of the transportation 
plan to ensure that new projects will not cause or worsen any new or 
existing hot-spot violations. In addition, we clarified that in some 
cases modeling the last year of the transportation plan or the year of 
project completion may not be sufficient to satisfy this requirement. 
EPA believes that the most effective means to meet this requirement 
would be to have the hot-spot analysis examine the year(s) during the 
time frame of the plan in which project emissions, in addition to 
background regional emissions in the project area, are expected to be 
the highest. Today's final rule simply incorporates EPA's existing 
interpretation of the rule's hot-spot requirements into the conformity 
regulations.
    EPA received a number of comments on our proposed clarification of 
Sec.  93.116. One commenter believed that the transportation planning 
process should not be interrupted due to the inexact data on which the 
process is based.
    Today's changes to Sec.  93.116 do not impose any new requirements. 
Rather, this final rule clarifies that when a hot-spot analysis is 
performed, the year or years that are analyzed must be the year(s) when 
project emissions, in addition to background regional emissions in the 
project area, are expected to be the highest and violations are most 
likely to occur. We believe that most areas are already successfully 
complying with this hot-spot requirement, and consequently, changes to 
the existing planning process due to the final rule are not expected.
    The remaining commenters requested additional guidance on 
implementing the clarification to Sec.  93.116. Specifically, one 
commenter indicated that their state currently requires CO hot-spot 
analyses for new projects in nonattainment and maintenance areas to 
examine air quality impacts of the project over a period extending up 
to 20 years after the project opens. This commenter argued that this 
protocol for analyzing the year of project completion and a horizon 
year typically 20 years from project completion is very likely to 
capture the highest emissions expected from the project. However, the 
commenter was concerned that EPA's clarification to Sec.  93.116 may 
not allow continued use of this protocol.
    EPA does not believe that the hot-spot analysis procedures employed 
by this state are necessarily inconsistent with today's clarification. 
In fact, this protocol could be more conservative since it requires the 
analysis of years beyond the 20 year time frame of an area's 
transportation plan or regional emissions analysis. EPA does not 
believe that the clarification to Sec.  93.116 would cause this state 
to revise its requirements for hot-spot analyses in most cases. EPA 
should note, however, that all hot-spot analyses performed in any 
nonattainment or maintenance areas should consider whether the 
combination of project emissions and background emissions could result 
in a violation occurring prior to the final year of the analysis 
period. Further, since areas are required to prevent hot-spot 
violations in years covered by the transportation plan, states should 
ensure that the use of the year of estimated highest projected 
emissions for a given project is sufficient to demonstrate that no 
violations would be expected during this time frame. Decisions 
regarding such analyses and year(s) chosen for hot-spot analyses should 
be determined through an area's interagency consultation process.
    Another commenter requested clarification as to whether areas would 
be required to analyze more than one year if peak project emissions and 
peak background emissions are expected to occur in different years. EPA 
does not intend for the revised Sec.  93.116 to require areas to 
analyze multiple years in all cases where peak project emissions and 
background emissions occur at different points in time. Instead, EPA 
intends for areas to analyze the year in which combined project and 
background emissions could most likely cause a violation or worsen an 
existing violation of the air quality standard. In some cases, however, 
a more conservative approach to meeting the conformity rule's 
requirements for hot-spot analyses would be to analyze more than one 
year within the time frame of the transportation plan or regional 
emissions analysis depending upon the local circumstances regarding 
peak project and background emissions. An area's interagency 
consultation process should be used to determine the appropriate 
year(s) for conducting hot-spot analyses in this type of situation.
    One commenter requested that EPA revise the clarification to Sec.  
93.116 to take into account the situation where a project would not 
remain in place over a 20-year time period. This situation could occur 
if a project is scheduled to be built and opened for use in stages. 
Specifically, the commenter requested that the clarification be revised 
to require that the hot-spot analysis cover the time frame of the plan 
``or time frame of the proposed project, whichever is shorter.''
    EPA does not believe that this commenter's suggested clarification 
is necessary. In the case of a project that is being built and opened 
for use in stages, the conformity rule allows the area's interagency 
consultation process to select the appropriate hot-spot analysis years. 
EPA believes that in these cases the local consultation process 
provides the best forum for deciding how to model such projects 
appropriately. Furthermore, the clarification to Sec.  93.116 allows 
areas to select an appropriate analysis year(s) to demonstrate that the 
project conforms over the entire time frame of an area's transportation 
plan or regional emissions analysis. It is likely that when a project 
is opened in stages, more than one analysis year may be necessary to 
satisfy the hot-spot requirements, as various years could produce 
significantly different emissions. For example, if a project were being 
opened in two stages and the entire two-stage project was being 
approved, the interagency consultation process may result in a decision 
to analyze two years. In this case, the first analysis year would be 
chosen to examine the impacts of the first stage of the project, such 
as a year between the opening of the first stage and the opening of the 
second stage of the project. The second analysis year would be chosen 
to examine the impacts of the complete project, such as a year between 
the opening of the second stage and the final year of the area's 
transportation plan or regional emissions analysis. Finally, EPA does 
not believe that the final rule is problematic with respect to projects 
that do not remain in effect for the entire time frame of the 20-year 
transportation plan. For example, if a project is only scheduled to be 
implemented for the first 10 years of the transportation plan, there 
would be no projected emissions from that project to consider for hot-
spot analysis in the latter 10 years of the plan.
    Another commenter encouraged EPA and DOT to issue hot-spot guidance 
that maintains and enforces significance thresholds and consider more 
stringent mitigation measures for exceedances of the thresholds. EPA 
does not believe that the requested guidance is needed or required to 
implement the Clean Air Act or conformity rule's requirements for 
ensuring that localized emissions from a new project do not cause or 
contribute to violations of the air quality standards. EPA believes 
that section 176(c)(3)(B)(ii)

[[Page 40058]]

of the Clean Air Act and Sec.  93.116 of the conformity rule establish 
sufficient requirements for addressing localized air quality problems 
in CO and PM10 nonattainment and maintenance areas. Further, 
EPA does not believe that exceedances of significant threshold levels 
would necessarily contribute to increased violations of a given air 
quality standard.
    Finally, one commenter asked when EPA intends to issue guidance on 
quantitative PM10 hot-spot analyses, as referred to in Sec.  
93.123(b)(4) of the conformity rule. As part of the November 5, 2003 
proposal (68 FR 62690), EPA requested comment on the experience areas 
have had in applying the conformity rule's PM10 hot-spot 
analysis requirements and on the need to maintain or amend these 
requirements. As noted in Section XIII. of today's action, EPA intends 
to decide on the PM10 hot-spot analysis requirement, 
including needs for quantitative analysis guidance, based on our review 
of comments from the November 2003 proposal and a future supplemental 
proposal.

XXII. Relying on a Previous Regional Emissions Analysis

A. Description of Final Rule

    EPA is finalizing three revisions to Sec.  93.122(g), which 
describes when an area can rely on a previous regional emissions 
analysis for a new conformity determination. EPA notes that the 
provisions for relying on a previous analysis were located in Sec.  
93.122(e) of the former conformity rule, but are being moved to Sec.  
93.122(g) due to reorganization of this section. First, EPA is revising 
Sec.  93.122(g) so that MPOs can rely on a previous regional emissions 
analysis for minor transportation plan revisions. Prior to today's 
final rule, Sec.  93.122(g) (Sec.  93.122(e) of the previous conformity 
rule) allowed areas to rely on a previous emissions analysis only for 
conformity determinations made for minor TIP updates or amendments. To 
meet Sec.  93.122(g) requirements, minor revisions to the 
transportation plan may include no additions or deletions of regionally 
significant projects, no significant changes in the design concept and 
scope of existing regionally significant projects, and no changes to 
the time frame of the transportation plan. Further, minor plan 
revisions under Sec.  93.122(g) would not include revisions that delay 
or accelerate the completion of regionally significant projects across 
conformity analysis years.
    EPA's second revision adds Sec.  93.122(g)(3) to clarify that a 
conformity determination that relies on a previous analysis does not 
satisfy the three-year frequency requirement for plans and TIPs. The 
conformity rule continues to require a new regional emissions analysis 
that incorporates the latest planning assumptions and emissions models 
at least every three years. In response to comments EPA received on 
this proposed rule change, EPA is also clarifying the three-year 
regional emissions analysis requirement in Sec.  93.104(b) and (c) of 
the rule.
    EPA's third revision adds Sec.  93.122(g)(1)(iv) and amends Sec.  
93.122(g)(2) to clarify that conformity determinations that rely on a 
previous regional emissions analysis must be based on all adequate and 
approved SIP budgets that apply at the time that DOT makes its 
conformity determination. Like all conformity determinations, a 
determination that relies on a previous emissions analysis must satisfy 
the emissions test requirements of Sec.  93.118 (or of Sec.  93.119, if 
no applicable budgets exist), and must do so over the time frame of the 
transportation plan. Therefore, EPA believes that pursuant to Sec.  
93.118(a) of the current rule, any conformity determination that relies 
on a previous emissions analysis must show consistency with all 
applicable adequate or approved budgets that are available for 
conformity purposes at the time the determination is made, including 
those budgets that have become applicable since the previous conformity 
determination. In other words, in cases where new adequate or approved 
budgets become available after the most recent conformity 
determination, the previous regional emissions analysis could be used 
for a subsequent determination if the emissions estimates from that 
analysis are at or below the emissions levels established by the new 
budgets for relevant years and all other Sec.  93.122(g) requirements 
are met. In this case, the conformity determination that includes the 
new budgets would also satisfy any applicable 18-month conformity 
requirement, pursuant to Sec.  93.104(e) that is triggered by EPA's 
adequacy finding and/or approval action of the new SIP budgets.
    This final rule applies to conformity determinations for plans, 
TIPs, and projects not from a conforming plan and TIP. EPA expects that 
most conformity implementers already consider new budgets when they 
rely on a previous emissions analysis. Today's final rule simply 
clarifies existing requirements and ensures that the conformity 
regulation continues to be correctly implemented in the future.
    EPA also notes that we are not altering the existing Sec.  
93.122(g)(2)(i) and (ii) provisions in today's final rule, as the June 
30, 2003 proposed regulatory text may have been confusing with regard 
to the specific changes that were proposed. In the preamble to the June 
30, 2003 proposed regulatory text, we stated that we were amending 
Sec.  93.122(g)(2) to clarify that a conformity determination that 
relies on a previous emissions analysis must be based on all adequate 
and approved budgets that apply when the determination is made. 
However, we only intended to amend the introductory text for Sec.  
93.122(g)(2) and did not intend to delete the existing subparagraphs 
Sec.  93.122(g)(2)(i) and (ii) for this provision, as may have appeared 
from the printed regulatory text. Therefore, we are now clarifying that 
subparagraphs Sec.  93.122(g)(2)(i) and (ii) still apply. That is, a 
project that is not from a conforming plan and TIP may be demonstrated 
to conform without a new regional emissions analysis if the project is 
either not regionally significant, or is included in the currently 
conforming transportation plan (even if it is not included in the 
currently conforming TIP) and its design concept and scope have not 
significantly changed and are sufficient for determining regional 
emissions. EPA believes that a reproposal is not necessary to make this 
correction in today's final rule, as this clarification is consistent 
with EPA's original intentions and stakeholders' understanding of the 
proposed revision to the Sec.  93.122(g)(2) provision.

B. Rationale and Response to Comments

    EPA believes that relying on a previous emissions analysis for 
minor transportation plan changes is appropriate, since such changes do 
not impact regional air quality and usually occur in tandem with minor 
TIP updates and amendments. The purpose of Sec.  93.122(g) is to allow 
areas to use a previous emissions analysis when no significant changes 
to the transportation system are being made. Through implementing Sec.  
93.122(g) over the years (as Sec.  93.122(e)), EPA has concluded that 
because plan and TIP updates often occur together, the purpose of this 
provision has been frustrated due to the rule's past applicability only 
to TIPs, but not plans.
    Most commenters supported EPA's proposal to allow areas to rely on 
a previous emissions analysis for minor transportation plan revisions. 
As stated in the June 30, 2003 proposal, the purpose of this final rule 
is to require a new regional emissions analysis only for transportation 
actions that involve

[[Page 40059]]

significant air quality impacts and at least every three years. One 
commenter, however, requested clarification on whether changes or 
additions to a plan and TIP would be determined ``significant'' through 
the interagency consultation process.
    EPA articulates its intentions for when transportation planners can 
rely on a previous emissions analysis in the existing conformity rule 
and the preamble to the November 24, 1993 conformity rule. 
Specifically, in the 1993 final rule, we stated that a new regional 
analysis would not be required ``if the only changes to the TIP involve 
either projects which are not regionally significant and which were not 
or could not be modeled in a regional emissions analysis, or changes to 
project design concept and scope which are not significant * * * '' (58 
FR 62202). Today's final rule clarifies that a previous analysis can 
only be used under similar circumstances for the plan, and when the 
time frame of the transportation plan has not changed. Under the 
consultation provisions of the conformity rule, the interagency 
consultation process should be used to determine which projects are 
``regionally significant'' for the purposes of regional emissions 
analyses, and which projects have a significant change in design 
concept and scope (Sec.  93.105(c)(2)(ii)). Therefore, EPA believes 
that the conformity rule clearly specifies that an area's interagency 
consultation process should be used for determining whether any changes 
or additions to a plan and/or TIP are not ``significant'' for the 
purposes of relying on a previous emissions analysis in accordance with 
Sec.  93.122(g).
    Another commenter requested EPA to identify comprehensively the 
circumstances when reliance on a previous regional emissions analysis 
would not be appropriate. Specifically, this commenter asked EPA to 
clarify that an area cannot rely on a previous analysis if new or 
revised planning assumptions and/or emissions models become available 
after the previous conformity determination. The commenter also 
requested that EPA clarify that an area cannot rely on a previous 
emissions analysis when new SIP budgets have become available for 
conformity purposes since the last determination. The commenter argued 
that since the Clean Air Act requires conformity determinations to be 
based on the most recent planning assumptions and emissions estimates, 
the conformity rule should require a new regional emissions analysis 
for all minor plan and TIP changes if new planning information becomes 
available after the previous analysis and conformity determination are 
made.
    In general, EPA agrees that Clean Air Act section 176(c)(1)(B)(iii) 
requires conformity determinations to be based on the most recent 
estimates of emissions. However, we also believe that Clean Air Act 
section 176(c)(4)(B)(ii) gives EPA discretion in establishing the 
requirements for a new regional emissions analysis when a minor change 
to a transportation plan and/or TIP is made. Specifically, section 
176(c)(4)(B)(ii) requires EPA to promulgate conformity rules that 
``address the appropriate frequency for making conformity 
determinations, but in no case shall such determinations for 
transportation plans and programs be less frequent than every three 
years, * * *.'' To satisfy this statutory requirement, EPA promulgated 
rules in 1993 (58 FR 62188) that require a new regional emissions 
analysis and conformity determination to be conducted at a minimum of 
every three years and when a significant change to the TIP is made 
between the three-year conformity frequency requirement.
    EPA does not believe that the Clean Air Act requires a new regional 
analysis to be triggered between three-year conformity updates in the 
case when minor project changes are made to the plan or TIP that would 
not affect regional emissions. Since the original November 24, 1993 
conformity rule, EPA has held that only the three-year conformity 
frequency requirement and transportation actions that involve 
significant air quality impacts should drive the necessity for a new 
regional emissions analysis that incorporates the most recent planning 
information. EPA does not believe, however, that a new emissions 
analysis should be required for the sole purposes of incorporating new 
planning information or models in between the three-year minimum 
conformity requirement. The conformity rule has never required a new 
emissions analysis in this case and EPA is not reopening this aspect of 
Sec.  93.122(g) in this rulemaking.
    As we have stated elsewhere in this final rule, conducting 
conformity determinations and regional emissions analyses to satisfy 
the conformity rule requires a significant amount of state and local 
resources. In the January 11, 1993 conformity proposal, we stated that 
``conformity determinations should be made frequently enough to ensure 
that the conformity process is meaningful. At the same time, EPA 
believes it is important to limit the number of triggers for conformity 
determinations in order to preserve the stability of the transportation 
planning process'' (58 FR 3775). EPA believes that requiring a new 
regional emissions analysis to incorporate new data and models for 
minor changes to transportation systems would essentially result in 
another conformity trigger whenever planning assumptions or models are 
updated. EPA believes such a trigger would be overly burdensome and in 
contrast with our stated goals of implementing a meaningful conformity 
process that limits disruption to the transportation planning process.
    In the 1993 conformity rule, EPA concluded that areas should be 
granted flexibility for meeting the conformity requirements for minor 
interim TIP updates and amendments under Sec.  93.122(g), even if new 
planning information becomes available after the previous analysis and 
conformity determination are made. See the January 11, 1993 proposal to 
the November 24, 1993 rule (58 FR 3778) for further background. EPA 
continues to believe such flexibility is appropriate and consistent 
with statutory requirements, and is not re-proposing nor re-opening the 
existing Sec.  93.122(g) requirement for minor TIP changes in this 
rulemaking. This final rule simply extends Sec.  93.122(g) requirements 
to minor plan revisions for consistency purposes. EPA believes this 
rule change will not have a significant impact on air quality, as the 
rule's existing frequency requirements will ultimately ensure that 
timely emissions analyses are conducted so that air quality is not 
worsened over the time frame of the long range transportation plan.
    In addition, EPA has always believed that requiring a new regional 
emissions analysis simply because new SIP budgets have become available 
since the last conformity determination is also unnecessary. In our 
1993 proposed conformity rule, we specifically stated, ``If the 
existing emissions analysis for the current transportation plan 
demonstrates that the current plan is consistent with the new 
implementation plan budget, a conformity finding can be made for the 
current plan. The transportation plan would not need to be revised and 
a new regional emissions analysis would not be necessary'' (58 FR 
3775). Today's rule ensures that any adequate or approved budgets that 
have become available since the previous conformity determination are 
incorporated in subsequent determinations. However, EPA believes that 
it is unnecessary to require a new regional emissions analysis when new 
budgets are incorporated, if a minor revision to the plan/TIP meets the 
current requirements of Sec.  93.122(g) and

[[Page 40060]]

conforms to the new budgets for relevant years. Again, EPA has not 
reopened this previous conclusion in today's rulemaking.
    A few commenters also disagreed with the new provision, Sec.  
93.122(g)(3), that clarifies that a conformity determination that 
relies on a previous regional emissions analysis does not satisfy the 
three-year frequency requirement for plans and TIPs. These commenters 
believe that conformity determinations that rely on a previous analysis 
should not be treated differently from any other determination. One of 
these commenters argued that since the frequency requirements in Sec.  
93.104 do not specifically include a requirement to perform a new 
regional emissions analysis, a conformity determination that relies on 
a previous analysis meets all the applicable conformity criteria and 
should satisfy the three-year conformity frequency requirement. The 
commenter also stated that requiring a conformity determination with a 
new analysis to meet the three-year conformity requirement shortly 
after making a conformity determination that relies on Sec.  93.122(g), 
would place an inappropriate burden on states and MPOs with no 
significant air quality benefit.
    As previously stated, EPA has always interpreted the Clean Air Act 
as requiring a conformity determination with a new regional emissions 
analysis that incorporates the latest planning information and models 
at a minimum of every three years. In our 1993 conformity proposal, we 
specifically stated that an ``emissions analysis must occur at least 
every three years'' (58 FR 3775), and we believe this requirement is 
necessary to fulfill the Clean Air Act's three-year conformity 
frequency requirement. Further, EPA has concluded that a new emissions 
analysis every three years will provide significant air quality 
benefits that justify the additional effort. As a result of this 
interpretation, we believe that Clean Air Act section 176(c)(4)(B)(ii) 
precludes a conformity determination that is based on a previous 
regional emissions analysis from satisfying the three-year requirement. 
EPA believes that the existing rule's requirements for a new regional 
emissions analysis that incorporates the latest planning information 
and models every three years, and for plan/TIP updates and amendments 
that include significant changes, are important for ensuring that 
transportation activities are consistent with an area's clean air 
goals. Thus, EPA cannot agree with these commenters' request.
    However, EPA agrees that the requirement for a new regional 
emissions analysis every three years could be clarified. Therefore, in 
response to this comment EPA is clarifying in Sec.  93.104(b)(3) and 
(c)(3) of today's action that MPOs and DOT must make a conformity 
determination that includes a new regional emissions analysis for 
transportation plans and TIPs no less frequently than every three 
years. This minor revision to Sec.  93.104 will not change existing 
requirements or implementation practices, as EPA expects that all 
metropolitan nonattainment and maintenance areas already conduct a new 
regional emissions analysis at a minimum of every three years. This 
rule revision simply clarifies existing requirements and ensures that 
the conformity regulation continues to be correctly implemented in the 
future.
    Finally, one commenter requested that EPA expand Sec.  93.122(g) so 
that a minimal number of new projects and/or project revisions could be 
added to a plan or TIP without having to do a new conformity 
determination at all. Such an approach, as suggested by this commenter, 
could be considered as a ``de minimis test'' for triggering a new 
determination.
    EPA does not believe that the Clean Air Act permits minor plan and 
TIP changes to occur without a conformity determination. Clean Air Act 
section 176(c) states that no approval or funding of any transportation 
plan, TIP or project can be granted unless that plan, TIP or project 
conforms. Therefore, the statute does not support the addition of a 
minimal number of new non-exempt projects and/or project revisions to 
the transportation plan or TIP without a conformity determination. In 
addition, the existing conformity rule already includes a list of 
exempt projects that never need conformity determinations due to their 
minimal air quality impact (Sec.  93.126). EPA believes that only plan 
and TIP updates involving these exempt projects should be allowed to 
proceed without a conformity determination.
    Furthermore, Sec.  93.122(g) of the conformity rule already 
provides a streamlined process for meeting the conformity requirement 
for minor plan and TIP changes in between the three-year conformity 
requirement by eliminating the need for a new regional emissions 
analysis. EPA believes this provision provides appropriate flexibility 
in meeting the statute's requirements, as well as a necessary ``check'' 
to ensure through the interagency consultation and public processes 
that such plan/TIP changes are indeed insignificant with regard to air 
quality. In addition, such determinations ensure that other 
requirements of the Clean Air Act and conformity rule (e.g., timely 
implementation of TCMs) are satisfied.

XXIII. Miscellaneous Revisions

A. Definitions

    In today's rulemaking, EPA is clarifying the conformity rule's 
definitions for ``control strategy implementation plan revision,'' 
``milestone,'' ``donut areas,'' and ``isolated rural nonattainment and 
maintenance areas'' in Sec.  93.101. Today's clarifications to these 
definitions should not impose any new requirements on nonattainment and 
maintenance areas; these rule revisions simply clarify EPA's original 
intent and current implementation of the existing conformity rule.
Control Strategy Implementation Plan Revision
    The final rule clarifies that any implementation plan revisions 
that are submitted to fulfill any of the following Clean Air Act 
requirements are considered control strategy SIPs for conformity 
purposes: section 172(c) and 187(g) or 189(d), in addition to the 
currently listed sections 182(b)(1), 182(c)(2)(A), and 182(c)(2)(B) for 
ozone areas; section 187(a)(7) for CO areas; sections 189(a)(1)(B) and 
189(b)(1)(A) for PM10 areas; and sections 192(a) and 192(b) 
for NO2 areas. We are also clarifying that any SIP that is 
established to demonstrate reasonable further progress and/or 
attainment should be considered a control strategy SIP.
    Several commenters supported EPA's clarification to the definition 
since it did not change the conformity frequency requirements in Sec.  
93.104(e). Specifically, these commenters understood that the 
definition change would not alter how initial submissions of control 
strategy SIPs or approvals of control strategy SIPs would trigger the 
18-month frequency requirement for a new conformity determination. EPA 
agrees with these comments.
    Another commenter believed that maintenance plans required under 
section 175A also constitute control strategy SIPs and suggested that 
this type of SIP be added to the definition. EPA disagrees with this 
comment. Control strategy implementation plans are plans developed by 
nonattainment areas for reasonable further progress or attainment 
purposes, as indicated by the above referenced Clean Air Act sections. 
In contrast, maintenance plans are developed by areas once they have

[[Page 40061]]

attained the applicable standard and, as such, would not fit this 
definition. Maintenance plans are already defined in Sec.  93.101 of 
the conformity rule, and Sec.  93.118 distinguishes between how control 
strategy SIPs and maintenance plans are applied when regional emissions 
analyses are completed with SIPs. For these reasons, EPA will not 
expand the definition of control strategy SIP to include maintenance 
plans.
Milestone
    Similarly, EPA is expanding the current definition of milestone to 
more adequately reflect EPA's original intent and implementation of 
this term. The final rule expands this definition so that it includes 
any year for which a motor vehicle emissions budget has been 
established to satisfy Clean Air Act requirements for demonstrating 
reasonable further progress. This definition includes all years in the 
applicable SIP for which emissions targets showing progress towards 
attainment are established in any nonattainment area.
    Several commenters supported EPA's clarification to the milestone 
definition and further urged EPA to encourage states to eliminate old 
motor vehicle emission budgets when submitting new SIPs or SIP 
revisions with new budgets. Commenters believed that eliminating old 
budgets would alleviate some confusion over which budgets and which 
milestones apply when more than one SIP is in place for the same 
pollutant.
    EPA does not agree with this comment. SIPs are legal documents 
which establish air quality control strategies and measures required 
for attaining and maintaining the standard. SIPs are developed for more 
than one Clean Air Act purpose, and each SIP is developed with 
different planning assumptions and could, thus, generate a different 
budget as well as potentially address different years. These SIPs and 
their associated budgets each play a role in an area's attainment 
strategy and cannot be eliminated simply for convenience in the 
conformity process. However, there may be some cases where budgets were 
developed for a Clean Air Act purpose for a year that is no longer 
applicable for future conformity determinations. Previously established 
SIPs can only be revised after satisfying applicable Clean Air Act 
requirements through the SIP process.
    EPA believes that there are already mechanisms for clarifying which 
SIP budgets apply for a given conformity determination. Section 
93.118(b) of the conformity rule clarifies which budgets are to be used 
and under what conditions. In addition, areas should use the 
interagency consultation process to ensure that Sec.  93.118 is being 
met and to determine which SIP budgets are applicable for conformity 
determinations where multiple SIPs are established. For these reasons, 
EPA believes that no further clarifications or changes to the 
regulations are necessary.
Donut Areas and Isolated Rural Nonattainment and Maintenance Areas
    In this final rule, ``donut areas'' are defined as geographic areas 
outside a metropolitan planning area boundary as designated under 23 
U.S.C. 134 and 49 U.S.C. 5303, but inside the boundary of a designated 
nonattainment/maintenance area that contains any part of a metropolitan 
area(s). ``Isolated rural nonattainment and maintenance areas'' are 
defined as any nonattainment or maintenance area that does not contain 
or is not part of any metropolitan planning area as designated under 23 
U.S.C. 134 and 49 U.S.C. 5303. Isolated rural areas do not have 
metropolitan transportation plans or TIPs required under 23 U.S.C. 134 
and 49 U.S.C. 5303 and 5304 and do not have projects that are part of 
the emissions analysis of any MPO's metropolitan transportation plan or 
TIP. Projects in such areas are instead included in statewide 
transportation improvement programs. EPA notes, however, that some 
isolated rural areas may also include projects in the statewide 
transportation plan. Whatever the case, projects in isolated rural 
areas that are included in both the statewide plan and statewide TIP 
would be included in regional emissions analyses for the area 
consistent with Sec.  93.109(l)(2)(i) of the final rule (formerly Sec.  
93.109(g)(2)(i)). Emissions analyses for these areas would also include 
any existing or planned regionally significant non-federal projects in 
the nonattainment or maintenance area.
    EPA is finalizing these definitions to clarify how areas that are 
designated nonattainment or maintenance, but that are not within the 
planning boundary of any MPO's jurisdiction, should be considered for 
conformity purposes. In general, commenters agreed with these 
definitions. Two commenters, however, raised concerns about the 
proposed definition of ``donut areas.'' These commenters believed that 
the phrase ``that is dominated by a metropolitan area(s)'' that was 
included in the June 30, 2003 proposal to this final rule was confusing 
and ambiguous. For example, one commenter stated that this phrase 
introduces uncertainty about how rural areas that are in a separate 
nonattainment area, but adjacent to an MPO in a different nonattainment 
or maintenance area for the same pollutant, would be treated. The 
commenter claimed that the phrase ``is dominated by'' raises an 
unnecessary question about the status of such rural areas, and to 
address this issue, EPA should revise its definition to more closely 
follow standard practice.
    After consideration of these comments, EPA agrees that the proposed 
definition for donut areas did not accurately reflect our intentions 
for how these areas should be defined. Therefore, in this final rule we 
have replaced the phrase ``is dominated by'' with the phrase ``contains 
any part of'' to clarify our intentions. Historically, EPA has always 
regarded donut areas as rural areas that are located in a nonattainment 
or maintenance area that also contains all or part of a metropolitan 
area. In contrast, isolated rural areas are located in nonattainment or 
maintenance areas that do not contain any part of a metropolitan area. 
We believe this simple change to the final rule definition better 
reflects how donut areas have been defined, in practice, and will 
ensure that rural areas are appropriately classified under the 
conformity regulations. EPA believes that a reproposal is not necessary 
to incorporate this minor change in today's final rule, as this 
clarification is consistent with EPA's original intentions and 
stakeholder's understanding of the proposed regulatory definitions.

B. Areas With Insignificant Motor Vehicle Emissions

    EPA is finalizing two rule revisions to incorporate our existing 
insignificance policy in the conformity rule. First, we are adding a 
new provision, Sec.  93.109(k), which applies to nonattainment and 
maintenance areas where EPA finds that the SIP's motor vehicle 
emissions for a pollutant or precursor for a given standard are an 
insignificant contributor to an area's regional air quality problem. 
This provision waives the regional emissions analysis requirements in 
Sec. Sec.  93.118 and 93.119 for an insignificant pollutant or 
precursor in these areas upon the effective date of EPA's adequacy 
finding or approval of such a SIP. In addition, this provision waives 
the hot-spot requirements in Sec. Sec.  93.116 and 93.123 in CO and 
PM10 areas if EPA also determines that the SIP demonstrates 
that potential localized hot-spot emissions are not a concern. Section 
93.109(k) also establishes the minimum criteria that are necessary to 
demonstrate that motor vehicle emissions are insignificant, as 
described below.

[[Page 40062]]

    Second, EPA is adding a new Sec.  93.121(c) to the rule to address 
regionally significant non-federal projects in areas where EPA has 
found a pollutant or precursor to be regionally insignificant. The new 
Sec.  93.121(c) allows regionally significant non-federal projects to 
be approved without being included in a regional emissions analysis for 
a pollutant or precursor that EPA has found insignificant, since such 
analyses will no longer be conducted. Sections 93.121(a) and (b) 
require that the emissions impacts of regionally significant non-
federal projects be considered prior to project approval. However, a 
regional analysis is not required for a pollutant or precursor for a 
given standard that EPA has found insignificant. Consistent with the 
new Sec.  93.109(k) for federal projects, the new Sec.  93.121(c) 
provision allows a non-federal project to be approved, without a 
regional emissions analysis otherwise required per Sec. Sec.  93.118 
and/or 93.119, for a regionally insignificant pollutant or precursor.
    Under this final rule and the existing policy, areas with 
insignificant regional motor vehicle emissions for a pollutant or 
precursor are still required to make a conformity determination that 
satisfies other relevant requirements including: timely implementation 
of TCMs in an approved SIP, interagency and public consultation, hot-
spot requirements including the use of latest planning assumptions and 
emissions models in CO and PM10 areas (if EPA has not made a 
finding that such emissions are also not a concern), and compliance 
with SIP control measures in PM10 and PM2.5 
areas. Areas are also required to satisfy the regional emissions 
analysis requirements in Sec. Sec.  93.118 and/or 93.119 for pollutants 
or precursors for which EPA has not made a finding of insignificance. 
For non-federal regionally significant projects, the requirements in 
either Sec.  93.121(a) or (b) apply for any other pollutants or 
precursors for which the area is designated nonattainment or 
maintenance that are considered significant (i.e., those pollutants or 
precursors that EPA has not determined to be insignificant at the 
regional level).
Rationale and Response to Comments
    As described in the preamble to the November 5, 2003 proposal, EPA 
developed the insignificance policy to provide flexibility for areas 
where motor vehicle emissions had little to no impact on an area's air 
quality problem. EPA believes that requiring these areas to perform a 
regional emissions analysis is not necessary to meet Clean Air Act 
section 176(c) requirements that transportation actions not worsen air 
quality, since the overall contribution of motor vehicle emissions in 
these areas is small and thus any significant change in such emissions 
over time would be unlikely. To date, approximately a dozen areas have 
taken advantage of the insignificance policy, consisting mainly of 
PM10 areas with air quality problems caused primarily by 
stationary or area sources. This current universe of areas has not 
changed significantly since 1993, and we do not anticipate the number 
of areas that could demonstrate insignificance of regional motor 
vehicle emissions to substantially increase in the future. Therefore, 
the final rule waives the regional emissions analysis requirement in 
these areas without compromising air quality, since state and local 
resources could then be directed toward reducing emissions from those 
sources that do contribute the most to an area's air quality problem.
    All who commented on insignificance supported incorporating our 
insignificance policy into the conformity rule. Commenters thought 
including the policy would help a limited number of areas, and one 
commenter specifically stated it would reduce burden without 
endangering air quality. One commenter requested that requirements for 
federal and non-federal projects be consistent in areas where EPA has 
found a pollutant or precursor to be insignificant. These requirements 
are in fact consistent under the final rule as explained above, because 
no regional emissions analysis is required for either type of project 
to be approved in these areas.
    A few commenters suggested that the insignificance provisions 
should be expanded to apply with respect to the PM2.5 
standard. We want to clarify that they in fact do apply for the 
PM2.5 standard. These insignificance provisions could apply 
to any standard for which conformity is determined, including 
PM2.5.
    Furthermore, the new Sec. Sec.  93.109(k) and 93.121(c) are 
consistent with the provisions of the rule in Sec. Sec.  93.102 and 
93.119 that address insignificance of pollutants before and after a SIP 
is submitted. See Section IX. for final rule amendments that address 
when re-entrained road dust emissions are considered significant for 
PM2.5 analyses.
    A few commenters suggested EPA include additional elements in the 
conformity rule. One commenter, for example, asked that EPA provide a 
definition of insignificance, and guidance on how such a determination 
would be made. However, EPA believes that the final rule is sufficient 
to implement the insignificance provisions in that it incorporates our 
existing guidance from the proposal to the 1997 rule (July 9, 1996, 61 
FR 36118) into Sec.  93.109(k). Rather than a ``one-size-fits-all'' 
definition, EPA's existing policy as articulated in this and previous 
conformity rulemakings and the new Sec.  93.109(k) gives EPA and the 
states the ability to examine whether motor vehicles are a significant 
contributor to regional and hot-spot air quality on a case-by-case 
basis, while still providing a framework for EPA's action. Another 
commenter suggested that the criteria for determining insignificance be 
expanded to include an area's impact on downwind areas. EPA does not 
believe a rule change is necessary to accommodate the concern of this 
commenter and thus is not changing the final rule in response to this 
comment. Again, EPA will look at SIPs that claim insignificance on a 
case-by-case basis consistent with the guidance provided in Sec.  
93.109(k), including their effects on downwind areas.
    A third commenter expressed concern that motor vehicle emissions 
could go from insignificant to significant simply because a reduction 
of emissions from other source sectors results in motor vehicle 
emissions comprising a greater percentage of the area's total 
inventory. EPA recognizes that this may occur. Initial inventories and 
strategies to attain or maintain air quality standards may change over 
time. Any changes to the significance of motor vehicle emissions must 
be discussed through interagency consultation in SIP development.
    This example also illustrates the reason EPA believes it is 
important to have flexibility in implementing this provision. Although 
the commenter specifically mentions 10% as the threshold for finding 
motor vehicle emissions insignificant, EPA clarifies that this figure 
is a general guideline only. Depending on the circumstances, we may 
find that motor vehicle emissions that make up less than 10% of an 
area's total inventory are still significant. Conversely, we may also 
find that motor vehicle emissions in excess of 10% are still 
insignificant, under certain circumstances relating to the overall 
composition of the air quality situation. In general, the percentage of 
motor vehicle emissions in the area's total inventory is an important 
criterion for determining whether motor vehicles are a significant or 
insignificant contributor to an area's air quality problem, yet there 
are other criteria that EPA will examine when

[[Page 40063]]

making this finding, as described in the regulatory text for Sec.  
93.109(k).
    Another comment we received on this section was with respect to 
hot-spot analyses. The commenter suggested that if motor vehicles are 
found to be an insignificant contributor to regional PM10, 
then hot-spot analyses should no longer be required in all cases. EPA 
disagrees with this comment, because a project could still cause a 
PM10 hot-spot even when motor vehicle emissions of 
PM10 are not regionally significant. For example, the 
projects listed in Sec.  93.127 of the conformity rule are exempt from 
regional emissions analysis because it is recognized that these 
projects are unlikely to affect emissions on a regional scale, but the 
local effects of these projects with respect to CO or PM10 
concentrations must still be considered to determine if a hot-spot 
analysis is required.
    Finally, we received several comments that insignificance should be 
addressed during the SIP development process with full opportunity for 
interagency consultation. EPA agrees with these commenters: as we said 
in the preamble to the November 5, 2003 proposal, it is appropriate 
that the claim of insignificance be reviewed via the interagency 
consultation process during the development of the SIP. If it is 
determined that regional and/or hot-spot motor vehicle emissions are 
insignificant, such a finding should be clearly stated and well 
supported in a SIP that is subsequently submitted to EPA for adequacy 
review and/or approval. We anticipate that interagency consultation 
regarding insignificance will occur as a result of the requirement for 
consultation on the development of the SIP in Sec.  93.105(b) of the 
conformity rule. Further, the public will have appropriate 
opportunities to comment on proposed findings of insignificance in the 
process of both state adoption, EPA SIP approval and adequacy finding 
of submitted SIPs.

C. Limited Maintenance Plans

    EPA is finalizing three rule revisions that would make the 
conformity rule consistent with EPA's existing limited maintenance plan 
policies for the 1-hour ozone, CO, and PM10 standards. 
Today's rule revisions also allow for any future limited maintenance 
plan policies for other standards to be considered in the conformity 
process. In general, a limited maintenance plan policy allows a 
nonattainment area with air quality that is significantly below a 
standard to request redesignation through a more streamlined 
maintenance plan. EPA received no comments on its proposed conformity 
revisions for limited maintenance plan areas.
    First, EPA is adding a basic definition for ``limited maintenance 
plan'' to Sec.  93.101 of the conformity rule. Second, we are including 
a new paragraph Sec.  93.109(j) that states that a regional emissions 
analysis is not required to satisfy Sec. Sec.  93.118 and/or 93.119 for 
pollutants in areas that have an adequate or approved limited 
maintenance plan for a given pollutant and standard. However, a 
conformity determination that meets other applicable criteria, 
including the hot-spot requirements for projects in CO and 
PM10 nonattainment and maintenance areas, interagency and 
public consultation, and timely implementation of TCMs in an approved 
SIP, is still required in these areas. A regional analysis also is 
required for any other pollutants or standards that otherwise apply but 
which are not the subject of a limited maintenance plan. The new Sec.  
93.109(j) requires a limited maintenance plan recognized under the 
conformity rule to have demonstrated that it would be unreasonable to 
expect that an area would experience enough motor vehicle emissions 
growth to cause a violation. The interagency consultation process 
should be used to discuss the development of a limited maintenance plan 
SIP (40 CFR 93.105(b)).
    Third, EPA is adding a new provision, Sec.  93.121(c), to clarify 
when funding and approval for new regionally significant non-federal 
projects is granted in areas with limited maintenance plans. Consistent 
with the new Sec.  93.109(j) for federal projects in areas with limited 
maintenance plans, this provision would not require a regional 
emissions analysis per Sec. Sec.  93.118 and/or 93.119 to be satisfied 
for regionally significant non-federal projects for the pollutant and 
standard that is addressed by the limited maintenance plan. However, 
the requirements in either Sec.  93.121(a) or (b) are required to be 
satisfied for any remaining pollutants or standards that apply in such 
an area that are not addressed by the limited maintenance plan.
    Based on the criteria for approving limited maintenance plans, EPA 
believes that violations of a standard for a pollutant due to 
unexpected regional growth would be highly unlikely in limited 
maintenance plan areas, although hot-spot violations could still occur. 
Furthermore, EPA considers it a reasonable assumption that motor 
vehicle emissions in an area that qualifies for a limited maintenance 
plan could increase to any realistic level during the maintenance 
period without causing or contributing to a violation of the standard. 
As a result, the budgets in limited maintenance plans are treated as 
essentially not constraining for the length of the maintenance period, 
and EPA believes that the Clean Air Act requirements to not worsen air 
quality are met presumptively without a regional conformity analysis. 
While this policy does not exempt an area from the need to determine 
conformity, it does eliminate the need for the regional emission 
analysis since EPA would be concluding through our adequacy review or 
approval of the limited maintenance plan that limits on motor vehicle 
emissions during the maintenance period are unnecessary, as long as the 
area maintains the standard.
    The revisions to Sec. Sec.  93.101, 93.109 and 93.121 in this final 
rule will not have a practical impact on how conformity is demonstrated 
in areas with applicable limited maintenance plans, as EPA is simply 
incorporating into the conformity rule our existing policies for these 
areas. The purpose of these rule revisions is to assist limited 
maintenance plan areas in their efforts to implement conformity. These 
revisions would in no way impose additional requirements for limited 
maintenance plan areas, nor would it eliminate any existing 
requirements applicable to such areas that could compromise air 
quality.
    For more information on transportation conformity and limited 
maintenance plans, see the preamble to the July 9, 1996 proposed 
conformity rule (61 FR 36118) and EPA's existing limited maintenance 
plan policies, which are available in the docket for this rulemaking as 
listed in Section I.B.1. For a discussion on EPA's adequacy review of 
limited maintenance plans, see the preamble to the June 30, 2003 
proposal (68 FR 38974).

D. Grace Period for Transportation Modeling and Plan Content 
Requirements in Certain Ozone and CO Areas

    EPA is finalizing three changes to the conformity rule to clarify 
when more rigorous transportation modeling and plan content 
requirements apply when circumstances change in certain ozone and CO 
areas. Today's rule revisions do not make any changes to the existing 
transportation plan content and modeling requirements.
    First, EPA is providing a two-year grace period in Sec.  93.122(c) 
before the more advanced transportation modeling requirements in Sec.  
93.122(b) are required in the following types of nonattainment areas or 
portions of such areas that are

[[Page 40064]]

not already required to meet these provisions:
     Ozone and CO areas that have an urbanized area population 
over 200,000 and are reclassified to a serious or higher classification 
(e.g., such a moderate ozone area that is reclassified to serious);
     Serious and above ozone and CO areas in which the 
urbanized area population increases to over 200,000; and
     Newly designated ozone and CO nonattainment areas that are 
classified as serious or above in which the urbanized area population 
is over 200,000.

    EPA is clarifying in the final rule that the grace period covers 
areas or portions of areas that need additional start-up time to meet 
new requirements, as described further below.
    Second, EPA is expanding the types of areas covered by the current 
rule's grace period for transportation plan content requirements. Under 
the previous rule, Sec.  93.106(b) provided a two-year grace period 
before the more specific transportation plan requirements in Sec.  
93.106(a) applied in moderate ozone and CO areas that were reclassified 
to serious and had urbanized populations over 200,000. EPA crafted the 
rule that way because it believed at the time that only such areas 
would need additional time to implement the more sophisticated 
transportation planning requirements. Today's final rule provides that 
same flexibility to nonattainment areas or portions of areas that are 
not already required to meet these requirements and are:
     Ozone areas that have an urbanized area population over 
200,000 that are reclassified to a serious or higher classification 
(e.g., such a moderate ozone area that is reclassified to serious),
     Serious and above ozone and CO areas in which the 
urbanized area population increases to over 200,000; and
     Newly designated ozone and CO nonattainment areas that are 
classified as serious or above in which the urbanized area population 
is over 200,000.

    EPA is clarifying the final rule so that these types of areas and 
portions of such areas which will also need time to implement newly 
applicable planning requirements are explicitly covered by the grace 
period, as originally intended.
    Third, EPA is clarifying in both Sec. Sec.  93.106(b) and 93.122(c) 
that the two-year grace periods begins upon either the:
     Effective date of EPA's action that reclassifies an ozone 
or CO area with an urbanized area population over 200,000, to a serious 
or higher classification,
     Official notice by the Census Bureau that the urbanized 
area population is over 200,000, or
     Effective date of EPA's action that initially designates 
an area as a serious or above ozone or CO nonattainment area.
An example of an official notice by the Census Bureau would be an 
announcement in the Federal Register that the urbanized population in a 
metropolitan area has increased to over 200,000.
Rationale and Response to Comments
    In general, several commenters supported the two-year grace period 
as proposed, because it will allow additional time to meet new 
requirements when applicable. EPA is promulgating these rule revisions 
to provide flexibility as originally intended. For the reasons stated 
in the November 5, 2003 proposal (68 FR 62717-8), EPA believes the 
final rule achieves the appropriate flexibility by providing the grace 
period to all areas or portions of areas that become newly subject to 
these requirements, but need start-up time because they have not 
previously been subject to these requirements. In addition, EPA 
originally intended Sec. Sec.  93.106 and 93.122 of the conformity rule 
to work together to provide start-up time when circumstances change, 
and providing a two-year grace period for both the plan content and 
modeling requirements achieves this goal.
    EPA is clarifying that the grace period will apply in portions of 
nonattainment areas, rather than entire areas, that are newly affected 
and are then required to meet the more rigorous requirements. For 
example, if a serious 8-hour nonattainment area is designated and 
includes additional counties to those within the previous serious 1-
hour nonattainment area, the grace period would only apply to those 
additional counties.
    In addition, the final rule clarifies how the grace period applies 
in newly designated 8-hour ozone nonattainment areas, or portions of 
such areas, that are initially classified as serious or above with an 
urbanized area population over 200,000, and that have not previously 
been subject to Sec. Sec.  93.106(a) and 93.122(b) requirements. EPA 
believes that it has good cause to finalize a grace period for these 
newly designated areas, even though the proposal did not specifically 
propose to provide the grace period to such areas. EPA intended the 
grace period to apply to these newly designated areas as well, since it 
is reasonable that such an area, or portion of such an area, would also 
need additional time to specify its networks and gather additional data 
to develop a more specific plan and conduct more advanced 
transportation modeling. Requesting further public comment on this 
detail is unnecessary, since EPA believes it has already received any 
comments that would have been submitted on such a minor clarification. 
Consistent with the intention and spirit of the proposal, EPA has 
clarified the final regulatory language to provide the grace period in 
these areas.
    One commenter believed that allowing a two-year grace period for 
the development of regional transportation plans is not reasonable for 
areas that were already subject to this requirement because they have 
previously been designated serious or above. An example of this case 
would be an 8-hour ozone area classified as moderate that was 
previously classified as serious under the 1-hour ozone standard. The 
commenter argued that Clean Air Act section 176(c)(6) requires that 
these areas continue to be subject to the requirements that applied 
under the ``preexisting'' air quality standard.
    EPA agrees with the commenter that areas that were previously 
subject to more rigorous transportation plan content and modeling 
requirements should continue to meet them. EPA did not intend to change 
this aspect of the existing rule with the proposal. Sections 93.106(c) 
and 93.122(d) (formerly Sec.  93.122(c)) already require that if it had 
been the previous practice of MPOs to meet these requirements, they 
must continue to do so. In response, EPA has revised the final rule 
language to clarify that the grace period does not apply to those 
areas, or portions of such areas, that are already required to meet 
these requirements for an existing NAAQS.
    Another commenter supported EPA's proposal, but noted that some 
transportation legislative proposals may change the transportation plan 
and TIP update intervals. This commenter suggested that EPA synchronize 
the grace period with the plan and TIP update periods to reduce the 
overall workload for planning agencies.
    EPA recognizes that Congress is currently considering various 
proposals for surface transportation reauthorization, which may amend 
transportation planning and/or transportation conformity provisions. 
However, EPA cannot promulgate regulations now against possible future 
statutory changes. We must promulgate regulations in light of the 
current law.

[[Page 40065]]

If changes to the transportation planning and conformity processes are 
passed into law, and those changes necessitate a regulatory change, EPA 
will propose and promulgate appropriate amendments to the rule at that 
time.
    In a similar light, a few other commenters stated that they opposed 
EPA's proposal because they believed that the grace period should be 
aligned with the transportation plan 3-year update cycle. They believed 
that such a grace period would be more adequate.
    EPA did not propose to change the length of the grace period, which 
was originally finalized as part of the November 24, 1993 conformity 
rule (58 FR 62188). EPA continues to believe that two years is an 
adequate time to meet applicable requirements. EPA must balance the 
benefits achieved by meeting the plan and modeling requirements, with 
the time needed to specify networks and perform the other data and 
collection activities necessary to develop network models and specific 
plans. See the preamble in the proposal for that rulemaking (January 
11, 1993, 58 FR 3776) for a discussion on the length of the two-year 
grace period. EPA continues to believe that a two-year period is an 
appropriate time span to accommodate these dual goals.
    EPA also intends to provide a full two-year grace period in all 
cases. The commenters' suggestion would result in a shorter grace 
period in cases where an area is covered by the new regulation in the 
middle of the plan update cycle. For example, suppose an area updates 
its plan in 2009, and receives official notice in 2011 from the Census 
Bureau that its population has increased above 200,000, based on the 
2010 census. Under commenters' suggestion that the grace period 
correspond to the plan update cycle, this area would have only one year 
to implement the transportation plan content and modeling requirements 
because its plan update and conformity determination, required every 
three years, would be due in 2012. EPA does not believe this would 
provide sufficient time for such an area to implement the plan content 
and modeling requirements.
    In cases of areas increasing in population, several commenters 
believed that the grace period should begin when DOT notifies an area 
of the change in population, rather than upon the Census Bureau's 
official notification in the Federal Register. They believed that such 
a change would allow for a more stable planning process and a more 
reliable start to the grace period.
    EPA disagrees with this approach for the following reasons. First, 
DOT does not issue formal notifications for all urbanized area 
definitions and changes. This is a Census Bureau function, and only the 
Census Bureau issues these notices. Although DOT issues a formal notice 
on the designation of transportation management areas (TMAs), this 
notification does not necessarily mean that the transportation plan 
content and modeling requirements in the conformity rule apply. 
Although most TMAs correspond to urbanized areas over 200,000 in 
population, DOT may also designate TMAs for certain areas under 200,000 
population, at the request of the Governor of a State. As described 
above, the current rule is based on urbanized area population, rather 
than TMA status. Therefore, changing the plan and modeling requirements 
to align with TMA designations may unintentionally apply these 
requirements to additional areas. Therefore, EPA is finalizing the rule 
as proposed, utilizing the Census Bureau's notification as the starting 
date for the grace period.
    Finally, one commenter who also supported the proposal requested 
further information regarding the selection of 200,000 as the threshold 
population. The 200,000 population threshold was finalized as part of 
the August 15, 1997 conformity rule (62 FR 43780). The preamble in the 
proposal for that rulemaking (July 9, 1996, 61 FR 36122) discussed 
EPA's rationale to limiting these requirements to areas with urbanized 
area populations over 200,000. In general, EPA chose the 200,000 
population level because it is also the population level used to 
delineate transportation management areas (TMAs), and because this 
limitation would ensure that smaller urban or rural areas would not be 
subject to more rigorous network modeling procedures and methods. EPA 
continues to believe that the 200,000 level in urbanized areas is 
appropriate for the plan content and modeling requirements. EPA did not 
propose any changes to the 200,000 urbanized population level in this 
rulemaking, and this final rule does not amend this threshold 
established in the 1997 rulemaking.

E. Minor Clarification to the List of PM10 Precursors

    Today's final rule clarifies the list of PM10 precursors 
in Sec. Sec.  93.102(b)(2)(iii) and 93.119(f)(5) of the conformity 
rule. Under the revised Sec.  93.102(b)(2)(iii), only VOC and 
NOX are identified as PM10 precursors; i.e., 
PM10 is deleted from the list of PM10 precursors 
in this paragraph. We are finalizing this clarification because Sec.  
93.102(b)(1) already requires that direct PM10 emissions be 
addressed in conformity analyses in PM10 nonattainment and 
maintenance areas. Therefore, inclusion of direct PM10 as a 
PM10 precursor in Sec.  93.102(b)(2)(iii) is duplicative.
    The revisions to Sec.  93.119(f)(5) provide consistency with other 
pollutants and precursors discussed in this paragraph. Neither of these 
rule changes will affect conformity determinations in PM10 
nonattainment and maintenance areas.
    EPA received two comments on this clarification to the rule. Both 
commenters supported the change because it eliminates a source of 
confusion in the rule's references to PM10 and clarifies the 
requirements of the rule. One of these commenters requested that EPA 
further clarify a number of additional terms. EPA does not agree that 
further changes to the rule are required, since these terms are not 
used in the proposal for this final rule. Please see a more detailed 
response in the response-to-comments document for this rulemaking in 
our docket.

F. Clarification of Requirements for Non-Federal Projects in Isolated 
Rural Areas

    EPA is finalizing a minor clarification to Sec.  93.121(b)(1) of 
the conformity rule that addresses the conformity requirements for non-
federal projects in isolated rural nonattainment and maintenance areas. 
Specifically, the final rule requires a regionally significant non-
federal project to be included in the regional emissions analysis of 
the most recent conformity determination ``that reflects'' the portion 
of the statewide transportation plan and statewide transportation 
improvement program (STIP) which includes projects planned for the 
isolated rural nonattainment or maintenance area before the projects 
can be approved.
    Today's revision to 93.121(b)(1) is intended to clarify that 
conformity determinations in isolated rural nonattainment and 
maintenance areas should not be ``for'' the statewide transportation 
plan or STIP, as written in the previous rule. In the proposal for the 
original 1993 conformity rule, we explained that ``STIPs are not TIPs 
as the latter term is meant in Clean Air Act section 176(c), and that 
conformity therefore does not apply to [STIPs] directly'' (January 11, 
1993, 58 FR 62206). However, isolated rural areas do not develop 
metropolitan transportation plans and TIPs per DOT's planning 
regulations. Instead, conformity determinations in isolated rural 
nonattainment and maintenance areas should include those existing and 
planned projects that are within the area and that are reflected in the 
statewide

[[Page 40066]]

transportation plan and STIP, as well as any other regionally 
significant projects. This rule change simply clarifies the conformity 
requirements for isolated rural nonattainment and maintenance areas and 
should not have a practical impact on how conformity is demonstrated in 
these areas.
    EPA received one comment on this clarification to the rule. The 
commenter stated that as written the rule would allow regionally 
significant non-federal projects to be approved even if the most recent 
conformity determination for a plan and TIP was not approved. The 
commenter also indicated that EPA must change the rule to require that 
such approvals only occur when non-federal projects are included in a 
conformity determination for a conforming plan and TIP.
    EPA agrees that regionally significant non-federal projects in 
isolated rural areas can only be approved if they have been included in 
a regional emissions analysis supporting the most recent conformity 
determination for the nonattainment or maintenance area or if they have 
been included in a regional emissions analysis showing that the area 
would continue to conform consistent with the requirements of 
Sec. Sec.  93.118 and/or 93.119 for projects not from a conforming 
transportation plan and TIP. We agree that the term ``most recent 
conformity determination'' refers to the most recent conformity 
determination that has been made by U.S. DOT. However, we do not agree 
that the rule needs to be revised to address the commenter's concern 
that a regionally significant non-federal project could be approved 
even if the most recent conformity determination has not been approved. 
EPA promulgated this part of the regulatory text for isolated rural 
areas in 1997, and EPA did not propose a change through this 
rulemaking. EPA understands that in practice, areas have always 
interpreted this provision to refer to approved conformity 
determinations. Therefore, we believe that the regulated community 
understands that ``most recent conformity determination'' applies to 
the most recent approved determination since we are not aware that 
language in the rule has resulted in any issues or problems.
    The commenter also asserted that non-federal projects can only be 
approved if they are included in a conformity determination for a 
conforming TIP and plan. We disagree with the commenter's assertion as 
it pertains to the approval of regionally significant non-federal 
projects in isolated rural areas. Isolated rural areas are not required 
to prepare TIPs and plans. Only metropolitan areas are required to 
prepare these documents. Therefore, regionally significant non-federal 
projects in isolated rural projects may be approved as long as they 
meet the requirements of Sec.  93.121(b)(1) or (2), which are described 
above. That is, although emissions from the project would be included 
in emissions analyses, the projects themselves would not require 
conformity determinations.

G. Use of Adequate and Approved Budgets in Conformity

    As described in the June 30, 2003 and November 5, 2003 proposals to 
this final rule, EPA proposed to clarify in Sec.  93.109 for each 
criteria pollutant and standard that the budget test must be satisfied 
as required by Sec.  93.118 for conformity determinations made on or 
after any one of the following:
     The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted SIP is adequate,
     The publication date of EPA's approval of such a budget in 
the Federal Register, or
     The effective date of EPA's approval of such a budget in 
the Federal Register, if the approval is completed through direct final 
rulemaking.

Under this final rule change, the budget would be used in any 
conformity determination conducted after the first time one of these 
three EPA actions occurs. See Section XV. for further information.

H. Budget Test Requirements for the Attainment Year

    In this final rule, EPA is clarifying how Sec.  93.118(b) and (d) 
should be implemented when a budget is established for a year prior to 
the attainment year (e.g., a reasonable further progress budget). 
Specifically, we are amending Sec.  93.118(b) so that once an area has 
any control strategy SIP budget available for conformity purposes, 
conformity must be demonstrated using the ``budget test'' for the 
attainment year if the attainment year is within the time frame of the 
transportation plan. EPA believes that it is always appropriate to 
conduct a budget test for the attainment year if it is within the time 
frame of the transportation plan and an applicable control strategy 
budget is established, as explained in the June 30, 2003 proposal. 
Areas should use the interagency consultation process to determine the 
appropriate years for which the budget test must be performed. EPA 
received no comments on this proposed revision to the conformity rule.

I. Budget Test Requirements Once a Maintenance Plan Is Submitted

    EPA is also finalizing two minor changes to Sec.  93.118(b)(2) to 
clarify which budgets apply when an area has both control strategy SIP 
and maintenance plan budgets. First, EPA is clarifying Sec.  
93.118(b)(2)(iii) so that when a maintenance plan has been submitted, 
the budget test is also completed for a submitted adequate control 
strategy SIP budget that is established for any year within the time 
frame of the transportation plan. The previous Sec.  93.118(b)(2)(iii) 
explicitly required areas with submitted maintenance plans to show 
consistency only to approved control strategy SIPs, but not adequate 
control strategy SIPs. Today's action will ensure that new 
transportation plans and TIPs conform to all adequate and approved 
budgets that are established for years within the time frame of the 
transportation plan.
    Second, we are adding Sec.  93.118(b)(2)(iv) to clarify that the 
budget(s) established for the most recent prior year must be used for 
any analysis years that are selected before the last year of the 
maintenance plan to meet the requirements of Sec.  93.118(d)(2). The 
previous conformity rule did not explicitly cover the situation where 
an analysis year is selected before the last year of the maintenance 
plan. The final rule provides consistency between the budget test 
requirements for control strategy SIPs and maintenance plans, since 
today's Sec.  93.118(b)(2) language for maintenance plans mirrors 
language that already exists in Sec.  93.118(b)(1) for control strategy 
SIPs. If an area analyzes a year for which no applicable budgets exist 
(e.g., an intermediate year between an area's attainment year and the 
first maintenance budget year), the area should always use the most 
recent prior adequate or approved budget to demonstrate conformity. 
This rationale also applies in areas that are submitting their second 
required 10-year maintenance plan.
    EPA received several comments requesting further clarification of 
our proposed revisions to Sec.  93.118(b)(2). First, one commenter 
believed that the addition of Sec.  93.118(b)(2)(iv) that requires 
conformity to prior budgets preempted the requirements for a 
qualitative finding under Sec.  93.118(b)(2)(i). This commenter asked 
that the preamble explain under what circumstances a qualitative 
finding would be appropriate.
    Section 93.118(b)(2)(i) states that when a maintenance plan is 
submitted that does not establish budgets for any years other than the 
last year of the

[[Page 40067]]

maintenance plan, a qualitative finding must be made to ensure that 
there are no factors which would cause or contribute to a new violation 
or exacerbate an existing violation in the years before the last year 
of the maintenance plan. In our July 9, 1996 proposal, we stated our 
conclusion that a ``qualitative finding is necessary if the budget only 
addresses the last year of the maintenance plan, because the budget 
test alone is not sufficient to determine, as required by the Clean Air 
Act, that the transportation action will not cause a new violation. The 
emissions impacts in the initial ten years of the maintenance plan must 
be considered in some manner in order to determine conformity.''
    EPA still believes that a qualitative finding is necessary in all 
cases where a maintenance plan establishes budgets only for the last 
year of the 10-year maintenance period. However, we also believe that a 
regional emissions analysis and budget test using a previously 
established budget for a year prior to the last year of a maintenance 
plan, pursuant to Sec.  93.118(b)(2)(iv), may fulfill the requirement 
for a qualitative finding in certain cases where the analysis is done 
for a year early in the term of the maintenance plan. Areas should use 
the interagency consultation process to determine the specific basis 
and necessary level of analysis to meet the qualitative finding 
requirement under Sec.  93.118(b)(2)(i) as described in the June 1996 
rulemaking.
    Another commenter stated that the proposed revisions to Sec.  
93.118(b)(2) do not clearly reflect their understanding that a budget 
established for a year beyond the time frame of a SIP (i.e., an 
``outyear'' budget) may be greater than the budgets established for a 
reasonable further progress, attainment or maintenance year. This 
commenter appears to have misinterpreted Sec.  93.118(b)(2)(iii) and 
(iv), as EPA did not intend for these provisions to mean that budgets 
established for any years within the time frame of the transportation 
plan (e.g., outyear budgets) must be less than or equal to a control 
strategy or maintenance plan budget. EPA intended for the phrase 
``emissions * * * must be less than or equal'' to refer to the 
emissions projected from planned and existing transportation activities 
in a specific analysis year for the conformity analysis that would be 
compared to an applicable control strategy or maintenance plan budget. 
EPA agrees that budgets apply only for the year they are established 
and for any future analysis years up until the next future budget year. 
Areas may submit larger budgets for outyears so long as they 
demonstrate that the SIP continues to provide for attainment or 
maintenance of the relevant air quality standard in those years.
    Finally, one commenter requested that EPA clarify the regional 
emissions analysis requirements in Sec.  93.118(b) and (d) so that 
conformity to the applicable motor vehicle emissions budgets will 
continue to be affirmatively demonstrated during each of the years 
between budget years and not just for years in which the budget test is 
required. The commenter suggested that if regional emissions analyses 
are conducted for a budget year and a subsequent year during the time 
frame of the transportation plan, and both analyses are consistent with 
the SIP, then emissions in intervening years can be assumed to conform. 
However, if such analyses are not conducted and shown to conform in 
this manner (e.g., when the first analysis year is chosen for a year 
some time after the first applicable budget), the commenter believed a 
more targeted analysis is required to ensure conformity in intervening 
years. By not addressing this alleged deficiency in the rule, the 
commenter believed that EPA has failed to include the clarification in 
Sec.  93.118(b) and (d) most needed to serve the purposes of the Clean 
Air Act.
    EPA disagrees with this commenter and believes that the current 
rule's budget test and regional emissions analysis requirements in 
Sec.  93.118(b) and (d) are adequate for ensuring that transportation 
plans, programs and projects meet the conformity requirements of the 
Clean Air Act. Clean Air Act section 176(c) specifically requires 
emissions from transportation activities to be consistent with the 
motor vehicle emissions limits established in the SIP. However, the 
Clean Air Act is ambiguous about the specific time frame or years in 
which emissions tests or analyses must be conducted. In the 1993 
conformity rule (58 FR 62188), EPA concluded as a legal matter that a 
demonstration of conformity for specific budget test years reasonably 
spaced over the time frame of the transportation plan is sufficient for 
meeting the Clean Air Act requirements and ensuring that emissions from 
transportation activities do not cause violations, worsen existing 
violations or delay timely attainment of the air quality standards.
    Furthermore, conducting conformity determinations and regional 
emissions analyses in accordance with the current rule's requirements 
demands a significant amount of time and state and local resources. EPA 
believes it would be impractical and overly burdensome to require MPOs 
and state DOTs to conduct a budget test and regional emissions analysis 
for additional years within the time frame of a 20-year transportation 
plan than are already required. Based on EPA's interpretation of the 
Clean Air Act since 1993, we believe that the current rule's budget 
test and emissions analysis year requirements are consistent with the 
statute, reasonable to implement, and protective of public health. 
Moreover, EPA did not propose to alter this interpretation and thus, 
has not re-opened this aspect of the conformity rule in this 
rulemaking.

J. Exempt Projects

    Finally, we are making a minor revision to the list of exempt 
projects in Sec.  93.126 of the conformity rule. On December 21, 1999, 
DOT published a rule revision to its right-of-way regulation (64 FR 
71284) that changed the citation for emergency or hardship advance land 
acquisitions (revised citation: 23 CFR 710.503) -- activities that are 
currently exempt from the conformity process. As a result, we are 
revising Sec.  93.126 to make the conformity rule fully consistent with 
DOT's December 1999 rulemaking. This proposed revision in no way 
expands or reduces the types of land acquisitions that are exempt from 
transportation conformity; it merely updates the conformity rule's 
reference to be consistent with DOT's regulations.
    Commenters supported EPA's proposal to make the conformity 
regulations consistent with DOT's right-of-way regulations. However, 
one commenter asked EPA to broaden its revisions to the conformity 
rule's list of exempt projects. This commenter believed that the 
current list of exempt projects does not fully reflect all the types of 
projects that should be exempt from conformity, given the progress over 
the last decade in understanding the real-world air quality impacts of 
different types of transportation projects.
    EPA did not propose amendments or clarifications to the list of 
exempt projects in Sec. Sec.  93.126, 93.127 and 93.128, and therefore, 
cannot address the changes this commenter has suggested. Areas should 
use the interagency consultation process, including consultation with 
EPA, FHWA and FTA, to determine which projects in the area's 
transportation plan and TIP should be considered exempt under 
Sec. Sec.  93.126, 93.127 and 93.128 of the rule.

[[Page 40068]]

XXIV. Comments Not Related to Rulemaking

    Several commenters offered suggestions or raised concerns about 
aspects of the transportation conformity program that are not germane 
to this specific rulemaking. These aspects included the process for 
revising outyear SIP budgets; implementation of EPA and DOT's April 9, 
2000 Memorandum of Understanding; reauthorization of the Surface 
Transportation Act, currently entitled Transportation Equity Act for 
the 21st Century (or TEA-21), and other topics. These comments do not 
affect whether EPA should proceed with this final action. Because these 
comments are not germane to this action, EPA has not responded 
substantively to them.
    In addition, two commenters urged EPA to publish the entire 
conformity regulatory text when we issued today's final rule. These 
commenters stated that publication of the entire rule would make the 
regulation easier to understand and implement. In response to this 
comment, EPA will provide a complete version of the conformity 
regulations that includes today's final rule on our transportation 
conformity website listed in Section I.B.2. of this notice. Individuals 
can also obtain a copy of the conformity regulations that incorporate 
today's rule amendments from the next codification of the U.S. Code of 
Federal Regulations after this final rule is published in the Federal 
Register. A complete response to comments document is in the docket for 
this rulemaking. See Section I.B.2. of this final rule for more 
information regarding the relevant dockets and how to access additional 
information associated with this final rule.

XXV. How Does Today's Final Rule Affect Conformity SIPs?

    Clean Air Act section 176(c)(4)(C) currently requires states to 
submit revisions to their SIPs to reflect all of the federal criteria 
and procedures for determining conformity. States can choose to develop 
conformity SIPs as a memorandum of understanding (MOU), memorandum of 
agreement (MOA), or state rule. However, a state must have and use its 
authority to make an MOU or MOA enforceable as a matter of state law, 
if such mechanisms are used. Section 51.390(b) of the conformity rule 
specifies that after EPA approves any conformity SIP revision, the 
federal conformity rule no longer governs conformity determinations 
(for the sections of the federal conformity rule that are covered by 
the approved conformity SIP).
    EPA would like to clarify when provisions of today's final rule 
apply in nonattainment and maintenance areas with and without EPA-
approved conformity SIPs:
     All provisions relating to the new standards apply 
immediately in all nonattainment and maintenance areas upon the 
effective date of today's action because no prior conformity rules (or 
approved conformity SIPs) address these new standard requirements.
     All amendments that address provisions directly impacted 
by the March 2, 1999 court decision apply immediately in all 
nonattainment and maintenance areas upon the effective date of today's 
action. Although some areas have conformity SIPs that were approved 
prior to March 1999, provisions included in these SIPs that the court 
subsequently remanded to EPA for further rulemaking are no longer 
enforceable by law. As a result, all areas, including those with a 
previously approved conformity SIPs, have been operating under EPA and 
DOT's guidance that implements the court decision and will be governed 
by the relevant court-related provisions of today's action when they 
become effective.
     In some areas, EPA has already approved conformity SIPs 
that include other provisions from previous conformity rulemakings that 
EPA is revising in this final rule. In these areas, the Clean Air Act 
prohibits today's federal rule amendments that are not a direct result 
of the March 1999 court decision or specifically related to the new 
standards (e.g., streamlining the frequency of conformity 
determinations; revision to the latest planning assumptions 
requirement) from superceding the previously approved state rules. 
Therefore, these specific rule amendments will be effective in areas 
with approved conformity SIPs that include related rule provisions only 
when the state includes them in a SIP revision and EPA approves that 
SIP revision. EPA has no authority to disregard this statutory 
requirement for those portions of today's final rule.
     Areas without any approved conformity SIPs will be able to 
use immediately all of the conformity amendments that are included in 
today's final rule.

EPA will provide further guidance on when sections of the conformity 
rule can be used in the conformity process in areas with approved 
conformity SIPs to assist states in implementing these provisions. This 
guidance will be posted on EPA's transportation conformity Web site 
listed in Section I.B.2. of today's final rule.
    One commenter did not agree that areas with approved conformity 
SIPs should have to revise their SIP before provisions of the final 
rule become effective. The commenter argued that this requirement 
penalizes areas with approved conformity SIPs and poses an undue burden 
on these areas to develop and gain EPA's approval of a SIP revision.
    EPA believes that this commenter misunderstood the proposal which 
stated that amendments that address specific conformity requirements 
for the new standards can be used by all areas upon the effective date 
of today's final rule, whether or not an area currently has an approved 
conformity SIP addressing pre-existing standards. This is possible 
since specific conformity requirements for the new standards should not 
be included in any currently approved conformity SIPs.
    However, amendments in today's final rule that are for sections of 
the federal rule that are not specifically related to the new standards 
and that are not affected by a March 1999 court decision finding 
certain provisions illegal become effective in states with approved 
conformity SIPs only when the state includes the amended section in a 
conformity SIP revision and EPA approves that SIP revision. This is 
because such provisions of the federal rule that are being changed no 
longer apply directly in states with approved conformity SIPs covering 
those provisions. EPA will work with states to approve such revisions 
as expeditiously as possible through flexible administrative 
techniques, such as parallel processing or direct final rulemaking. 
EPA's further guidance, as described above, will assist in conformity 
SIP revisions for today's final rule.
    This same commenter supported a process such as that proposed in 
the Administration's SAFETEA legislation that would streamline the 
conformity SIP requirement so that only interagency consultation 
requirements would need to be included in such SIP revisions. EPA 
supports this legislation, and if it becomes law, EPA agrees that the 
conformity SIP requirement will be significantly streamlined without 
practically affecting the conformity process. However, until such 
legislation is adopted, EPA is bound by the current Clean Air Act, and 
Sec.  51.390 of the conformity rule continues to apply for conformity 
SIP revisions for this final rule.
    One commenter requested that EPA coordinate the finalization of the 
rulemakings that address the new standards and the March 1999 court

[[Page 40069]]

decision so that area's will only need to revise their conformity SIPs 
once. Coordinating the release of the two final rules will assist in 
using state resources most efficiently and avoid duplication. EPA 
agrees with this commenter, and recommends that state and local air 
agencies should address both rulemakings in the same conformity SIP 
revision, since today's final rule combines the majority of the 
conformity provisions from the previously separate rulemakings.

XXVI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866, [58 FR 51735 (October 4, 1993)] the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to OMB review and the requirements of the 
Executive Order. The Order defines ``significant regulatory action'' as 
one that is likely to result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or state, local, or tribal governments or 
communities;
    (2) create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Under the terms of Executive Order 12866, it has been determined 
that amendments in this rule that are related to conformity under the 
new air quality standards are a ``significant regulatory action.'' As 
such, this action was submitted to OMB for E.O. 12866 review. Changes 
made in response to OMB suggestions or recommendations will be 
documented in the public record.

B. Paperwork Reduction Act

    The information collection requirements for this final rule will be 
submitted for approval to the Office of Management and Budget (OMB) 
under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and as ICR 
2130.02. The information collection requirements are not enforceable 
until OMB approves them.
    Transportation conformity determinations are required under Clean 
Air Act section 176(c) (42 U.S.C. 7506(c)) to ensure that federally 
supported highway and transit project activities are consistent with 
(``conform to'') the purpose of the SIP. Conformity to the purpose of 
the SIP means that transportation activities will not cause new air 
quality violations, worsen existing violations, or delay timely 
attainment of the relevant air quality standards. Transportation 
conformity applies under EPA's conformity regulations at 40 CFR parts 
51.390 and 93 to areas that are designated nonattainment and those 
redesignated to attainment after 1990 (``maintenance areas'' with SIPs 
developed under Clean Air Act section 175A) for transportation-source 
criteria pollutants. The Clean Air Act gives EPA the statutory 
authority to establish the criteria and procedures for determining 
whether transportation activities conform to the SIP.
    Amendments in today's final rule that are related to conformity 
requirements in existing nonattainment and maintenance areas do not 
impose any new information collection requirements from EPA that 
require approval by OMB under the Paperwork Reduction Act of 1980, 44 
U.S.C. 3501 et seq. An agency may not conduct or sponsor, and a person 
is not required to respond to a collection of information, unless it 
displays a currently valid OMB control number. The information 
collection requirements of EPA's existing transportation conformity 
rule and any revisions in today's action for existing areas are covered 
under the DOT information collection request (ICR) entitled, 
``Metropolitan and Statewide Transportation Planning,'' with the OMB 
control number of 2132-0529.
    EPA provided two opportunities for public comment on the 
incremental burden estimates for transportation conformity 
determinations under the new 8-hour ozone and PM2.5 
standards. First, the November 5, 2003 proposal contained an initial 
annual burden estimate for conducting conformity determinations of 
$6,750 and 275 hours for each metropolitan area designated 
nonattainment for the first time for the 8-hour ozone and 
PM2.5 standards (e.g., areas that have never been subject to 
transportation conformity for any standard). EPA refined this burden 
estimate in the ICR that it released for public comment on January 5, 
2004 (69 FR 336). As described in the January 2004 ICR (ICR 2130.01), 
the estimated annual state and local burden for conformity activities 
in each metropolitan nonattainment area that is expected to incur 
additional burden under the new ozone and PM2.5 standards is 
estimated at 325 hours/year at a cost of $16,320/year. Additional 
federal burden associated with conformity for each of these 
metropolitan nonattainment areas is approximately 127 hours/year at a 
cost of $6,400/year. Average state and local burden associated with 
conformity for each isolated rural nonattainment area that incurs new 
burden under the new standards is 42 hours/year at a cost of $2,111/
year. New federal burden associated with each of these areas is 
calculated to be 10 hours/year at a cost of $503/year.
    EPA received comments on both the initial burden estimates provided 
in the November 5, 2003 proposal and on the revised estimates in the 
January 2004 ICR. EPA will respond to all of these comments in the 
final ICR that will be submitted to OMB for approval (ICR 2130.02).
    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a federal agency. This includes the time 
needed to review instructions; develop, acquire, install and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and, transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9. When ICR 2130.02 is 
approved by OMB, the Agency will publish a technical amendment to 40 
CFR part 9 in the Federal Register to display the OMB control number 
for the approved information collection requirements contained in this 
final rule.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act, as amended by the Small Business 
Regulatory Enforcement Fairness Act of 1996, requires the Agency to 
conduct a regulatory flexibility analysis of any significant impact a 
rule will have on a substantial number of small entities. Small 
entities include small businesses,

[[Page 40070]]

small not-for-profit organizations and small government jurisdictions.
    For purposes of assessing the impacts of today's final rule on 
small entities, small entity is defined as: (1) A small business as 
defined by the Small Business Administration's (SBA) regulations at 13 
CFR 121.201; (2) a small governmental jurisdiction that is a government 
of a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of today's final rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This 
regulation directly affects federal agencies and metropolitan planning 
organizations that, by definition, are designated under federal 
transportation laws only for metropolitan areas with a population of at 
least 50,000. These organizations do not constitute small entities 
within the meaning of the Regulatory Flexibility Act.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on state, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``federal mandates'' that 
may result in expenditures to state, local, and tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    EPA has determined that this final rule does not contain a federal 
mandate that may result in expenditures of $100 million or more for 
state, local, and tribal governments, in the aggregate, or the private 
sector in any one year. The primary purpose of this rulemaking is to 
amend the existing federal conformity regulations to cover areas newly 
designated nonattainment under the recently promulgated 8-hour ozone 
and PM2.5 air quality standards. Clean Air Act section 
176(c)(5) requires the applicability of conformity to such areas as a 
matter of law one year after nonattainment designations. Thus, although 
this rule explains how conformity should be conducted, it merely 
implements already established law that imposes conformity requirements 
and does not itself impose requirements that may result in expenditures 
of $100 million or more in any year.
    This rulemaking also formalizes what the U.S. Court of Appeals for 
the District of Columbia Circuit has already decided as a legal matter, 
and that is currently being implemented in practice. Additional rule 
amendments also addressed in this final rule simply serve to improve 
the conformity regulation by implementing the rule in a more 
practicable manner and/or to clarify conformity requirements that 
already exist. None of these rule amendments impose any additional 
burdens beyond that already imposed by applicable federal law; thus, 
today's final rule is not subject to the requirements of sections 202 
and 205 of the UMRA and EPA has not prepared a statement with respect 
to budgetary impacts.

E. Executive Order 13132: Federalism

    Executive Order 13132, Federalism (64 FR 43255, August 10, 1999), 
revokes and replaces Executive Orders 12612 (Federalism) and 12875 
(Enhancing the Intergovernmental Partnership). Executive Order 13132 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by State and local officials in the development of 
regulatory policies that have federalism implications.'' ``Policies 
that have federalism implications'' is defined in the Executive Order 
to include regulations that have ``substantial direct effects on the 
States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government.'' Under Executive Order 13132, EPA may 
not issue a regulation that has federalism implications, that imposes 
substantial direct compliance costs, and that is not required by 
statute, unless the Federal government provides the funds necessary to 
pay the direct compliance costs incurred by State and local 
governments, or EPA consults with state and local officials early in 
the process of developing the regulation. EPA also may not issue a 
regulation that has federalism implications and that preempts state law 
unless the Agency consults with state and local officials early in the 
process of developing the proposed regulation.
    If EPA complies by consulting, Executive Order 13132 requires EPA 
to provide to the Office of Management and Budget (OMB), in a 
separately identified section of the preamble to the rule, a federalism 
summary impact statement (FSIS). The FSIS must include a description of 
the extent of EPA's prior consultation with state and local officials, 
a summary of the nature of their concerns and the Agency's position 
supporting the need to issue the regulation, and a statement of the 
extent to which the concerns of state and local officials have been 
met. Also, when EPA transmits a draft rule with federalism implications 
to OMB for review pursuant to Executive Order 12866, EPA must include a 
certification from the Agency's Federalism Official stating that EPA 
has met the requirements of Executive Order 13132 in a meaningful and 
timely manner.
    This final rule, that amends a regulation that is required by 
statute, will not have substantial direct effects on the states, on the 
relationship between the national government and the states, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132. The Clean Air Act 
requires conformity to apply in certain nonattainment and maintenance 
areas as a matter of law, and this final rule merely establishes and 
revises procedures for transportation planning entities in subject 
areas to follow in meeting their existing statutory obligations.
    In addition, the U.S. Court of Appeals for the District of Columbia 
Circuit has determined that projects requiring federal approval and 
funding are affected when a nonattainment or

[[Page 40071]]

maintenance area is unable to demonstrate conformity. Specifically, 
under Clean Air Act section 176(c) those phases (NEPA approval, right-
of-way acquisition, final design, or construction) in a federal 
project's development that have not received federal approval or 
funding prior to a conformity lapse cannot be granted approval or 
funding, and thus proceed during a conformity lapse. Furthermore, the 
court directed EPA to establish new procedures for determining the 
adequacy of motor vehicle emissions estimates before such estimates can 
be used in conformity determinations to comply with Clean Air Act 
requirements. Similarly, other amendments included in this final rule 
are the result of either the court's order concerning the proper 
interpretation of the Clean Air Act and other related administrative 
matters, or have been proposed simply to make the rule more workable 
and/or to clarify requirements that already exist under the current 
conformity regulation.
    In summary, this final rule is required primarily by the statutory 
requirements imposed by the Clean Air Act, and the final rule by itself 
will not have a substantial impact on states. Thus, the requirements of 
section 6 of the Executive Order do not apply to this final rule.

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

    Executive Order 13175: ``Consultation and Coordination with Indian 
Tribal Governments'' (65 FR 67249, November 6, 2000) requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by tribal officials in the development of regulatory policies that have 
tribal implications.'' ``Policies that have tribal implications'' is 
defined in the Executive Order to include regulations that have 
``substantial direct effects on one or more Indian tribes, on the 
relationship between the Federal government and the Indian tribes, or 
on the distribution of power and responsibilities between the Federal 
government and Indian tribes.''
    Today's amendments to the conformity rule do not significantly or 
uniquely affect the communities of Indian tribal governments, as the 
Clean Air Act requires transportation conformity to apply in any area 
that is designated nonattainment or maintenance by EPA. Specifically, 
this final rule incorporates into the conformity rule provisions 
addressing newly designated nonattainment areas subject to conformity 
requirements under the Act, the court's interpretation of the Act, as 
well as several other clarifications and improvements, that have no 
substantial direct effects on tribal governments, on the relationship 
between the federal government and Indian tribes, or on the 
distribution of power and responsibilities between the federal 
government and Indian tribes, as specified in Executive Order 13175. 
Accordingly, the requirements of Executive Order 13175 are not 
applicable to this rulemaking.

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

    Executive Order 13045: ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies 
to any rule that: (1) Is determined to be ``economically significant'' 
as defined under Executive Order 12866, and (2) concerns an 
environmental health or safety risk that EPA has reason to believe may 
have a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    This final rule is not subject to Executive Order 13045 because it 
is not economically significant within the meaning of Executive Order 
12866 and does not involve the consideration of relative environmental 
health or safety risks.

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

    This rule is not subject to Executive Order 13211, ``Action 
Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use'' (66 FR 28355; May 22, 2001) because it will not 
have a significant adverse effect on the supply, distribution, or use 
of energy.

I. National Technology Transfer and Advancement Act

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

J. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. The EPA will submit this final rule and other required 
information to the U.S. Senate, the U.S. House of Representatives, and 
the Comptroller General of the United States prior to publication of 
the final rule in the Federal Register. This rule is not a ``major 
rule'' as defined by 5 U.S.C. 804(2). This rule will be effective on 
August 2, 2004.

K. Petitions for Judicial Review

    Under section 307(b)(1) of the Clean Air Act, petitions for 
judicial review of this action must be filed in the United States Court 
of Appeals for the appropriate circuit by August 30, 2004. Filing a 
petition for reconsideration by the Administrator of this final rule 
does not affect the finality of this rule for the purposes of judicial 
review, nor does it extend the time within which a petition for 
judicial review may be filed, and shall not postpone the effectiveness 
of such a rule or action. This action may not be challenged later in 
proceeding to enforce its requirements. (See section 307(b)(2) of the 
Administrative Procedures Act.)

List of Subjects in 40 CFR Part 93

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Carbon monoxide, Inter governmental relations, 
Nitrogen Dioxide, Ozone, Particulate matter, Transportation, Volatile 
organic compounds.

    Dated: June 14, 2004.
Michael O. Leavitt,
Administrator.
    For the reasons set out in the preamble, 40 CFR part 93 is amended 
as follows:

[[Page 40072]]

PART 93--[AMENDED]

0
1. The authority citation for part 93 continues to read as follows:

    Authority: 42 U.S.C. 7401-7671q.


0
2. Section 93.101 is amended by adding, in alphabetical order, new 
definitions for ``1-hour ozone NAAQS,'' ``8-hour ozone NAAQS,'' ``Donut 
areas,'' ``Isolated rural nonattainment and maintenance areas,'' and 
``Limited maintenance plan,'' and by revising definitions for ``Control 
strategy implementation plan revision'' and ``Milestone'' to read as 
follows:


Sec.  93.101  Definitions.

* * * * *
    1-hour ozone NAAQS means the 1-hour ozone national ambient air 
quality standard codified at 40 CFR 50.9.
* * * * *
    8-hour ozone NAAQS means the 8-hour ozone national ambient air 
quality standard codified at 40 CFR 50.10.
* * * * *
    Control strategy implementation plan revision is the implementation 
plan which contains specific strategies for controlling the emissions 
of and reducing ambient levels of pollutants in order to satisfy CAA 
requirements for demonstrations of reasonable further progress and 
attainment (including implementation plan revisions submitted to 
satisfy CAA sections 172(c), 182(b)(1), 182(c)(2)(A), 182(c)(2)(B), 
187(a)(7), 187(g), 189(a)(1)(B), 189(b)(1)(A), and 189(d); sections 
192(a) and 192(b), for nitrogen dioxide; and any other applicable CAA 
provision requiring a demonstration of reasonable further progress or 
attainment).
* * * * *
    Donut areas are geographic areas outside a metropolitan planning 
area boundary, but inside the boundary of a nonattainment or 
maintenance area that contains any part of a metropolitan area(s). 
These areas are not isolated rural nonattainment and maintenance areas.
* * * * *
    Isolated rural nonattainment and maintenance areas are areas that 
do not contain or are not part of any metropolitan planning area as 
designated under the transportation planning regulations. Isolated 
rural areas do not have Federally required metropolitan transportation 
plans or TIPs and do not have projects that are part of the emissions 
analysis of any MPO's metropolitan transportation plan or TIP. Projects 
in such areas are instead included in statewide transportation 
improvement programs. These areas are not donut areas.
* * * * *
    Limited maintenance plan is a maintenance plan that EPA has 
determined meets EPA's limited maintenance plan policy criteria for a 
given NAAQS and pollutant. To qualify for a limited maintenance plan, 
for example, an area must have a design value that is significantly 
below a given NAAQS, and it must be reasonable to expect that a NAAQS 
violation will not result from any level of future motor vehicle 
emissions growth.
* * * * *
    Milestone has the meaning given in CAA sections 182(g)(1) and 
189(c) for serious and above ozone nonattainment areas and 
PM10 nonattainment areas, respectively. For all other 
nonattainment areas, a milestone consists of an emissions level and the 
date on which that level is to be achieved as required by the 
applicable CAA provision for reasonable further progress towards 
attainment.
* * * * *

0
3. Section 93.102 is amended by:
0
a. Revising paragraphs (b)(1), (b)(2) introductory text and 
(b)(2)(iii);
0
b. Redesignating paragraph (b)(3) as paragraph (b)(4);
0
c. Adding a new paragraph (b)(3);
0
d. Revising paragraph (c); and
0
e. Revising paragraph (d).
    The revisions and additions read as follows:


Sec.  93.102  Applicability.

* * * * *
    (b) * * *
    (1) The provisions of this subpart apply with respect to emissions 
of the following criteria pollutants: ozone, carbon monoxide (CO), 
nitrogen dioxide (NO2), particles with an aerodynamic 
diameter less than or equal to a nominal 10 micrometers 
(PM10); and particles with an aerodynamic diameter less than 
or equal to a nominal 2.5 micrometers (PM2.5).
    (2) The provisions of this subpart also apply with respect to 
emissions of the following precursor pollutants:
* * * * *
    (iii) VOC and/or NOX in PM10 areas if the EPA 
Regional Administrator or the director of the State air agency has made 
a finding that transportation-related emissions of one or both of these 
precursors within the nonattainment area are a significant contributor 
to the PM10 nonattainment problem and has so notified the 
MPO and DOT, or if the applicable implementation plan (or 
implementation plan submission) establishes an approved (or adequate) 
budget for such emissions as part of the reasonable further progress, 
attainment or maintenance strategy.
    (3) The provisions of this subpart apply to PM2.5 
nonattainment and maintenance areas with respect to PM2.5 
from re-entrained road dust if the EPA Regional Administrator or the 
director of the State air agency has made a finding that re-entrained 
road dust emissions within the area are a significant contributor to 
the PM2.5 nonattainment problem and has so notified the MPO 
and DOT, or if the applicable implementation plan (or implementation 
plan submission) includes re-entrained road dust in the approved (or 
adequate) budget as part of the reasonable further progress, attainment 
or maintenance strategy. Re-entrained road dust emissions are produced 
by travel on paved and unpaved roads (including emissions from anti-
skid and deicing materials).
* * * * *
    (c) Limitations. In order to receive any FHWA/FTA approval or 
funding actions, including NEPA approvals, for a project phase subject 
to this subpart, a currently conforming transportation plan and TIP 
must be in place at the time of project approval as described in Sec.  
93.114, except as provided by Sec.  93.114(b).
    (d) Grace period for new nonattainment areas. For areas or portions 
of areas which have been continuously designated attainment or not 
designated for any NAAQS for ozone, CO, PM10, 
PM2.5 or NO2 since 1990 and are subsequently 
redesignated to nonattainment or designated nonattainment for any NAAQS 
for any of these pollutants, the provisions of this subpart shall not 
apply with respect to that NAAQS for 12 months following the effective 
date of final designation to nonattainment for each NAAQS for such 
pollutant.

0
4. Section 93.104 is amended by:
0
a. Revising the first sentence in paragraph (b)(3);
0
b. Revising the first sentence in paragraph (c)(3), and removing 
paragraph (c)(4);
0
c. Revising paragraph (d); and
0
d. Removing paragraphs (e)(1) and (e)(4) and redesignating paragraphs 
(e)(2), (e)(3) and (e)(5) as paragraphs (e)(1), (e)(2) and (e)(3), and 
by revising newly redesignated paragraphs (e)(2) and (e)(3).
    The revisions read as follows:


Sec.  93.104  Frequency of conformity determinations.

* * * * *
    (b) * * *

[[Page 40073]]

    (3) The MPO and DOT must determine the conformity of the 
transportation plan (including a new regional emissions analysis) no 
less frequently than every three years. * * *
    (c) * * *
    (3) The MPO and DOT must determine the conformity of the TIP 
(including a new regional emissions analysis) no less frequently than 
every three years. * * *
    (d) Projects. FHWA/FTA projects must be found to conform before 
they are adopted, accepted, approved, or funded. Conformity must be 
redetermined for any FHWA/FTA project if one of the following occurs: a 
significant change in the project's design concept and scope; three 
years elapse since the most recent major step to advance the project; 
or initiation of a supplemental environmental document for air quality 
purposes. Major steps include NEPA process completion; start of final 
design; acquisition of a significant portion of the right-of-way; and, 
construction (including Federal approval of plans, specifications and 
estimates).
    (e) * * *
    (2) The effective date of EPA approval of a control strategy 
implementation plan revision or maintenance plan which establishes or 
revises a motor vehicle emissions budget if that budget has not yet 
been used in a conformity determination prior to approval; and
    (3) The effective date of EPA promulgation of an implementation 
plan which establishes or revises a motor vehicle emissions budget.

0
5. Section 93.105(c)(1)(vii) is amended by revising the reference 
``Sec.  93.109(g)(2)(iii)'' to read ``Sec.  93.109(l)(2)(iii).''

0
6. Section 93.106 is amended by revising paragraph (b) to read as 
follows:


Sec.  93.106  Content of transportation plans.

* * * * *
    (b) Two-year grace period for transportation plan requirements in 
certain ozone and CO areas. The requirements of paragraph (a) of this 
section apply to such areas or portions of such areas that have 
previously not been required to meet these requirements for any 
existing NAAQS two years from the following:
    (1) The effective date of EPA's reclassification of an ozone or CO 
nonattainment area that has an urbanized area population greater than 
200,000 to serious or above;
    (2) The official notice by the Census Bureau that determines the 
urbanized area population of a serious or above ozone or CO 
nonattainment area to be greater than 200,000; or,
    (3) The effective date of EPA's action that classifies a newly 
designated ozone or CO nonattainment area that has an urbanized area 
population greater than 200,000 as serious or above.
* * * * *

0
7. Section 93.109 is amended by:
0
a. Revising the paragraph (b) introductory text;
0
b. In Table 1 of paragraph (b), revising the entry for ``Sec.  93.118 
or Sec.  93.119'' under ``Transportation Plan:'' and the entry for 
``Sec.  93.118 or Sec.  93.119'' under ``TIP:'', and revising the entry 
for ``Sec.  93.117'' under ``Project (From a Conforming Plan and 
TIP):'' and the entries for ``Sec.  93.117'' and ``Sec.  93.118 or 
Sec.  93.119'' under ``Project (Not From a Conforming Plan and TIP):''
0
c. Revising paragraph (c);
0
d. Redesignating paragraphs (d), (e), (f) and (g) as paragraphs (f), 
(g), (h) and (l);
0
e. Adding new paragraphs (d), (e), (i), (j) and (k);
0
f. Revising newly redesignated paragraphs (f) introductory text, 
(f)(2), (f)(3) and (f)(4)(i) and (ii);
0
g. Revising newly redesignated paragraphs (g) introductory text, 
(g)(2), and (g)(3);
0
h. Revising newly redesignated paragraph (h); and
0
i. Revising newly redesignated paragraph (l)(2) introductory text; in 
newly redesignated paragraph (l)(2)(ii)(B), revising ``Sec.  
93.119(d)(2)'' to read ``Sec.  93.119(f)(2)'' and, in newly 
redesignated paragraph (l)(2)(iii), revising ``paragraph (g)(2)(ii)'' 
and ``paragraph (g)(2)(ii)(C)'' to read ``paragraph (l)(2)(ii)'' and 
``paragraph (l)(2)(ii)(C)'', respectively.
    The revisions and additions read as follows:


Sec.  93.109  Criteria and procedures for determining conformity of 
transportation plans, programs, and projects: General.

* * * * *
    (b) Table 1 in this paragraph indicates the criteria and procedures 
in Sec. Sec.  93.110 through 93.119 which apply for transportation 
plans, TIPs, and FHWA/FTA projects. Paragraphs (c) through (i) of this 
section explain when the budget, interim emissions, and hot-spot tests 
are required for each pollutant and NAAQS. Paragraph (j) of this 
section addresses conformity requirements for areas with approved or 
adequate limited maintenance plans. Paragraph (k) of this section 
addresses nonattainment and maintenance areas which EPA has determined 
have insignificant motor vehicle emissions. Paragraph (l) of this 
section addresses isolated rural nonattainment and maintenance areas. 
Table 1 follows:

                                          Table 1.--Conformity Criteria
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
Transportation Plan:
 
                                                  * * * * * * *
    Sec.   93.118 and/or Sec.   93.119...  Emissions budget and/or Interim emissions.
 
                                                  * * * * * * *
TIP:
 
                                                  * * * * * * *
    Sec.   93.118 and/or Sec.   93.119...  Emissions budget and/or Interim emissions.
 
                                                  * * * * * * *
Project (From a Conforming Plan and TIP):
 
                                                  * * * * * * *
    Sec.   93.117........................  PM10 and PM2.5 control measures.
 

[[Page 40074]]

 
                                                  * * * * * * *
Project (Not From a Conforming Plan and
 TIP):
 
                                                  * * * * * * *
    Sec.   93.117........................  PM10 and PM2.5 control measures.
    Sec.   93.118 and/or Sec.   93.119...  Emissions budget and/or Interim emissions.
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

    (c) 1-hour ozone NAAQS nonattainment and maintenance areas. This 
paragraph applies when an area is nonattainment or maintenance for the 
1-hour ozone NAAQS (i.e., until the effective date of any revocation of 
the 1-hour ozone NAAQS for an area). In addition to the criteria listed 
in Table 1 in paragraph (b) of this section that are required to be 
satisfied at all times, in such ozone nonattainment and maintenance 
areas conformity determinations must include a demonstration that the 
budget and/or interim emissions tests are satisfied as described in the 
following:
    (1) In all 1-hour ozone nonattainment and maintenance areas the 
budget test must be satisfied as required by Sec.  93.118 for 
conformity determinations made on or after:
    (i) The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted control strategy implementation plan 
revision or maintenance plan for the 1-hour ozone NAAQS is adequate for 
transportation conformity purposes;
    (ii) The publication date of EPA's approval of such a budget in the 
Federal Register; or
    (iii) The effective date of EPA's approval of such a budget in the 
Federal Register, if such approval is completed through direct final 
rulemaking.
    (2) In ozone nonattainment areas that are required to submit a 
control strategy implementation plan revision for the 1-hour ozone 
NAAQS (usually moderate and above areas), the interim emissions tests 
must be satisfied as required by Sec.  93.119 for conformity 
determinations made when there is no approved motor vehicle emissions 
budget from an applicable implementation plan for the 1-hour ozone 
NAAQS and no adequate motor vehicle emissions budget from a submitted 
control strategy implementation plan revision or maintenance plan for 
the 1-hour ozone NAAQS.
    (3) An ozone nonattainment area must satisfy the interim emissions 
test for NOX, as required by Sec.  93.119, if the 
implementation plan or plan submission that is applicable for the 
purposes of conformity determinations is a 15% plan or Phase I 
attainment demonstration that does not include a motor vehicle 
emissions budget for NOX. The implementation plan for the 1-
hour ozone NAAQS will be considered to establish a motor vehicle 
emissions budget for NOX if the implementation plan or plan 
submission contains an explicit NOX motor vehicle emissions 
budget that is intended to act as a ceiling on future NOX 
emissions, and the NOX motor vehicle emissions budget is a 
net reduction from NOX emissions levels in 1990.
    (4) Ozone nonattainment areas that have not submitted a maintenance 
plan and that are not required to submit a control strategy 
implementation plan revision for the 1-hour ozone NAAQS (usually 
marginal and below areas) must satisfy one of the following 
requirements:
    (i) The interim emissions tests required by Sec.  93.119; or
    (ii) The State shall submit to EPA an implementation plan revision 
for the 1-hour ozone NAAQS that contains motor vehicle emissions 
budget(s) and a reasonable further progress or attainment 
demonstration, and the budget test required by Sec.  93.118 must be 
satisfied using the adequate or approved motor vehicle emissions 
budget(s) (as described in paragraph (c)(1) of this section).
    (5) Notwithstanding paragraphs (c)(1) and (c)(2) of this section, 
moderate and above ozone nonattainment areas with three years of clean 
data for the 1-hour ozone NAAQS that have not submitted a maintenance 
plan and that EPA has determined are not subject to the Clean Air Act 
reasonable further progress and attainment demonstration requirements 
for the 1-hour ozone NAAQS must satisfy one of the following 
requirements:
    (i) The interim emissions tests as required by Sec.  93.119;
    (ii) The budget test as required by Sec.  93.118, using the 
adequate or approved motor vehicle emissions budgets in the submitted 
or applicable control strategy implementation plan for the 1-hour ozone 
NAAQS (subject to the timing requirements of paragraph (c)(1) of this 
section); or
    (iii) The budget test as required by Sec.  93.118, using the motor 
vehicle emissions of ozone precursors in the most recent year of clean 
data as motor vehicle emissions budgets, if such budgets are 
established by the EPA rulemaking that determines that the area has 
clean data for the 1-hour ozone NAAQS.
    (d) 8-hour ozone NAAQS nonattainment and maintenance areas without 
motor vehicle emissions budgets for the 1-hour ozone NAAQS for any 
portion of the 8-hour nonattainment area. This paragraph applies to 
areas that were never designated nonattainment for the 1-hour ozone 
NAAQS and areas that were designated nonattainment for the 1-hour ozone 
NAAQS but that never submitted a control strategy SIP or maintenance 
plan with approved or adequate motor vehicle emissions budgets. This 
paragraph applies 1 year after the effective date of EPA's 
nonattainment designation for the 8-hour ozone NAAQS for an area, 
according to Sec.  93.102(d). In addition to the criteria listed in 
Table 1 in paragraph (b) of this section that are required to be 
satisfied at all times, in such 8-hour ozone nonattainment and 
maintenance areas conformity determinations must include a 
demonstration that the budget and/or interim emissions tests are 
satisfied as described in the following:
    (1) In such 8-hour ozone nonattainment and maintenance areas the 
budget test must be satisfied as required by Sec.  93.118 for 
conformity determinations made on or after:
    (i) The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted control strategy implementation plan 
revision or maintenance plan for the 8-hour ozone NAAQS is adequate for 
transportation conformity purposes;

[[Page 40075]]

    (ii) The publication date of EPA's approval of such a budget in the 
Federal Register; or
    (iii) The effective date of EPA's approval of such a budget in the 
Federal Register, if such approval is completed through direct final 
rulemaking.
    (2) In ozone nonattainment areas that are required to submit a 
control strategy implementation plan revision for the 8-hour ozone 
NAAQS (usually moderate and above and certain Clean Air Act, part D, 
subpart 1 areas), the interim emissions tests must be satisfied as 
required by Sec.  93.119 for conformity determinations made when there 
is no approved motor vehicle emissions budget from an applicable 
implementation plan for the 8-hour ozone NAAQS and no adequate motor 
vehicle emissions budget from a submitted control strategy 
implementation plan revision or maintenance plan for the 8-hour ozone 
NAAQS.
    (3) Such an 8-hour ozone nonattainment area must satisfy the 
interim emissions test for NOX, as required by Sec.  93.119, 
if the implementation plan or plan submission that is applicable for 
the purposes of conformity determinations is a 15% plan or other 
control strategy SIP that addresses reasonable further progress that 
does not include a motor vehicle emissions budget for NOX. 
The implementation plan for the 8-hour ozone NAAQS will be considered 
to establish a motor vehicle emissions budget for NOX if the 
implementation plan or plan submission contains an explicit 
NOX motor vehicle emissions budget that is intended to act 
as a ceiling on future NOX emissions, and the NOX 
motor vehicle emissions budget is a net reduction from NOX 
emissions levels in 2002.
    (4) Ozone nonattainment areas that have not submitted a maintenance 
plan and that are not required to submit a control strategy 
implementation plan revision for the 8-hour ozone NAAQS (usually 
marginal and certain Clean Air Act, part D, subpart 1 areas) must 
satisfy one of the following requirements:
    (i) The interim emissions tests required by Sec.  93.119; or
    (ii) The State shall submit to EPA an implementation plan revision 
for the 8-hour ozone NAAQS that contains motor vehicle emissions 
budget(s) and a reasonable further progress or attainment 
demonstration, and the budget test required by Sec.  93.118 must be 
satisfied using the adequate or approved motor vehicle emissions 
budget(s) (as described in paragraph (d)(1) of this section).
    (5) Notwithstanding paragraphs (d)(1) and (d)(2) of this section, 
ozone nonattainment areas with three years of clean data for the 8-hour 
ozone NAAQS that have not submitted a maintenance plan and that EPA has 
determined are not subject to the Clean Air Act reasonable further 
progress and attainment demonstration requirements for the 8-hour ozone 
NAAQS must satisfy one of the following requirements:
    (i) The interim emissions tests as required by Sec.  93.119;
    (ii) The budget test as required by Sec.  93.118, using the 
adequate or approved motor vehicle emissions budgets in the submitted 
or applicable control strategy implementation plan for the 8-hour ozone 
NAAQS (subject to the timing requirements of paragraph (d)(1) of this 
section); or
    (iii) The budget test as required by Sec.  93.118, using the motor 
vehicle emissions of ozone precursors in the most recent year of clean 
data as motor vehicle emissions budgets, if such budgets are 
established by the EPA rulemaking that determines that the area has 
clean data for the 8-hour ozone NAAQS.
    (e) 8-hour ozone NAAQS nonattainment and maintenance areas with 
motor vehicle emissions budgets for the 1-hour ozone NAAQS that cover 
all or a portion of the 8-hour nonattainment area. This provision 
applies 1 year after the effective date of EPA's nonattainment 
designation for the 8-hour ozone NAAQS for an area, according to Sec.  
93.102(d). In addition to the criteria listed in Table 1 in paragraph 
(b) of this section that are required to be satisfied at all times, in 
such 8-hour ozone nonattainment and maintenance areas conformity 
determinations must include a demonstration that the budget and/or 
interim emissions tests are satisfied as described in the following:
    (1) In such 8-hour ozone nonattainment and maintenance areas the 
budget test must be satisfied as required by Sec.  93.118 for 
conformity determinations made on or after:
    (i) The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted control strategy implementation plan 
revision or maintenance plan for the 8-hour ozone NAAQS is adequate for 
transportation conformity purposes;
    (ii) The publication date of EPA's approval of such a budget in the 
Federal Register; or
    (iii) The effective date of EPA's approval of such a budget in the 
Federal Register, if such approval is completed through direct final 
rulemaking.
    (2) Prior to paragraph (e)(1) of this section applying, the 
following test(s) must be satisfied, subject to the exception in 
paragraph (e)(2)(v):
    (i) If the 8-hour ozone nonattainment area covers the same 
geographic area as the 1-hour ozone nonattainment or maintenance 
area(s), the budget test as required by Sec.  93.118 using the approved 
or adequate motor vehicle emissions budgets in the 1-hour ozone 
applicable implementation plan or implementation plan submission;
    (ii) If the 8-hour ozone nonattainment area covers a smaller 
geographic area within the 1-hour ozone nonattainment or maintenance 
area(s), the budget test as required by Sec.  93.118 for either:
    (A) The 8-hour nonattainment area using corresponding portion(s) of 
the approved or adequate motor vehicle emissions budgets in the 1-hour 
ozone applicable implementation plan or implementation plan submission 
where such portion(s) can reasonably be identified through the 
interagency consultation process required by Sec.  93.105; or
    (B) The 1-hour nonattainment area using the approved or adequate 
motor vehicle emissions budgets in the 1-hour ozone applicable 
implementation plan or implementation plan submission. If additional 
emissions reductions are necessary to meet the budget test for the 8-
hour ozone NAAQS in such cases, these emissions reductions must come 
from within the 8-hour nonattainment area;
    (iii) If the 8-hour ozone nonattainment area covers a larger 
geographic area and encompasses the entire 1-hour ozone nonattainment 
or maintenance area(s):
    (A) The budget test as required by Sec.  93.118 for the portion of 
the 8-hour ozone nonattainment area covered by the approved or adequate 
motor vehicle emissions budgets in the 1-hour ozone applicable 
implementation plan or implementation plan submission; and
    (B) The interim emissions tests as required by Sec.  93.119 for 
either: the portion of the 8-hour ozone nonattainment area not covered 
by the approved or adequate budgets in the 1-hour ozone implementation 
plan, the entire 8-hour ozone nonattainment area, or the entire portion 
of the 8-hour ozone nonattainment area within an individual state, in 
the case where separate 1-hour SIP budgets are established for each 
state of a multi-state 1-hour nonattainment or maintenance area;
    (iv) If the 8-hour ozone nonattainment area partially covers a 1-
hour ozone nonattainment or maintenance area(s):
    (A) The budget test as required by Sec.  93.118 for the portion of 
the 8-hour

[[Page 40076]]

ozone nonattainment area covered by the corresponding portion of the 
approved or adequate motor vehicle emissions budgets in the 1-hour 
ozone applicable implementation plan or implementation plan submission 
where they can be reasonably identified through the interagency 
consultation process required by Sec.  93.105; and
    (B) The interim emissions tests as required by Sec.  93.119, when 
applicable, for either: the portion of the 8-hour ozone nonattainment 
area not covered by the approved or adequate budgets in the 1-hour 
ozone implementation plan, the entire 8-hour ozone nonattainment area, 
or the entire portion of the 8-hour ozone nonattainment area within an 
individual state, in the case where separate 1-hour SIP budgets are 
established for each state in a multi-state 1-hour nonattainment or 
maintenance area.
    (v) Notwithstanding paragraphs (e)(2)(i), (ii), (iii), or (iv) of 
this section, the interim emissions tests as required by Sec.  93.119, 
where the budget test using the approved or adequate motor vehicle 
emissions budgets in the 1-hour ozone applicable implementation plan(s) 
or implementation plan submission(s) for the relevant area or portion 
thereof is not the appropriate test and the interim emissions tests are 
more appropriate to ensure that the transportation plan, TIP, or 
project not from a conforming plan and TIP will not create new 
violations, worsen existing violations, or delay timely attainment of 
the 8-hour ozone standard, as determined through the interagency 
consultation process required by Sec.  93.105.
    (3) Such an 8-hour ozone nonattainment area must satisfy the 
interim emissions test for NOX, as required by Sec.  93.119, 
if the only implementation plan or plan submission that is applicable 
for the purposes of conformity determinations is a 15% plan or other 
control strategy SIP that addresses reasonable further progress that 
does not include a motor vehicle emissions budget for NOX. 
The implementation plan for the 8-hour ozone NAAQS will be considered 
to establish a motor vehicle emissions budget for NOX if the 
implementation plan or plan submission contains an explicit 
NOX motor vehicle emissions budget that is intended to act 
as a ceiling on future NOX emissions, and the NOX 
motor vehicle emissions budget is a net reduction from NOX 
emissions levels in 2002. Prior to an adequate or approved 
NOX motor vehicle emissions budget in the implementation 
plan submission for the 8-hour ozone NAAQS, the implementation plan for 
the 1-hour ozone NAAQS will be considered to establish a motor vehicle 
emissions budget for NOX if the implementation plan contains 
an explicit NOX motor vehicle emissions budget that is 
intended to act as a ceiling on future NOX emissions, and 
the NOX motor vehicle emissions budget is a net reduction 
from NOX emissions levels in 1990.
    (4) Notwithstanding paragraphs (e)(1) and (e)(2) of this section, 
ozone nonattainment areas with three years of clean data for the 8-hour 
ozone NAAQS that have not submitted a maintenance plan and that EPA has 
determined are not subject to the Clean Air Act reasonable further 
progress and attainment demonstration requirements for the 8-hour ozone 
NAAQS must satisfy one of the following requirements:
    (i) The budget test and/or interim emissions tests as required by 
Sec. Sec.  93.118 and 93.119 and as described in paragraph (e)(2) of 
this section;
    (ii) The budget test as required by Sec.  93.118, using the 
adequate or approved motor vehicle emissions budgets in the submitted 
or applicable control strategy implementation plan for the 8-hour ozone 
NAAQS (subject to the timing requirements of paragraph (e)(1) of this 
section); or
    (iii) The budget test as required by Sec.  93.118, using the motor 
vehicle emissions of ozone precursors in the most recent year of clean 
data as motor vehicle emissions budgets, if such budgets are 
established by the EPA rulemaking that determines that the area has 
clean data for the 8-hour ozone NAAQS.
    (f) CO nonattainment and maintenance areas. In addition to the 
criteria listed in Table 1 in paragraph (b) of this section that are 
required to be satisfied at all times, in CO nonattainment and 
maintenance areas conformity determinations must include a 
demonstration that the hot-spot, budget and/or interim emissions tests 
are satisfied as described in the following:
* * * * *
    (2) In CO nonattainment and maintenance areas the budget test must 
be satisfied as required by Sec.  93.118 for conformity determinations 
made on or after:
    (i) The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted control strategy implementation plan 
revision or maintenance plan is adequate for transportation conformity 
purposes;
    (ii) The publication date of EPA's approval of such a budget in the 
Federal Register; or
    (iii) The effective date of EPA's approval of such a budget in the 
Federal Register, if such approval is completed through direct final 
rulemaking.
    (3) Except as provided in paragraph (f)(4) of this section, in CO 
nonattainment areas the interim emissions tests must be satisfied as 
required by Sec.  93.119 for conformity determinations made when there 
is no approved motor vehicle emissions budget from an applicable 
implementation plan and no adequate motor vehicle emissions budget from 
a submitted control strategy implementation plan revision or 
maintenance plan.
    (4) * * *
    (i) The interim emissions tests required by Sec.  93.119; or
    (ii) The State shall submit to EPA an implementation plan revision 
that contains motor vehicle emissions budget(s) and an attainment 
demonstration, and the budget test required by Sec.  93.118 must be 
satisfied using the adequate or approved motor vehicle emissions 
budget(s) (as described in paragraph (f)(2) of this section).
    (g) PM10 nonattainment and maintenance areas. In addition to the 
criteria listed in Table 1 in paragraph (b) of this section that are 
required to be satisfied at all times, in PM10 nonattainment 
and maintenance areas conformity determinations must include a 
demonstration that the hot-spot, budget and/or interim emissions tests 
are satisfied as described in the following:
    (1) * * *
    (2) In PM10 nonattainment and maintenance areas the 
budget test must be satisfied as required by Sec.  93.118 for 
conformity determinations made on or after:
    (i) The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted control strategy implementation plan 
revision or maintenance plan is adequate for transportation conformity 
purposes;
    (ii) The publication date of EPA's approval of such a budget in the 
Federal Register; or
    (iii) The effective date of EPA's approval of such a budget in the 
Federal Register, if such approval is completed through direct final 
rulemaking.
    (3) In PM10 nonattainment areas the interim emissions 
tests must be satisfied as required by Sec.  93.119 for conformity 
determinations made:
    (i) If there is no approved motor vehicle emissions budget from an 
applicable implementation plan and no adequate motor vehicle emissions 
budget from a submitted control strategy

[[Page 40077]]

implementation plan revision or maintenance plan; or
    (ii) If the submitted implementation plan revision is a 
demonstration of impracticability under CAA section 189(a)(1)(B)(ii) 
and does not demonstrate attainment.
    (h) NO2 nonattainment and maintenance areas. In addition to the 
criteria listed in Table 1 in paragraph (b) of this section that are 
required to be satisfied at all times, in NO2 nonattainment 
and maintenance areas conformity determinations must include a 
demonstration that the budget and/or interim emissions tests are 
satisfied as described in the following:
    (1) In NO2 nonattainment and maintenance areas the 
budget test must be satisfied as required by Sec.  93.118 for 
conformity determinations made on or after:
    (i) The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted control strategy implementation plan 
revision or maintenance plan is adequate for transportation conformity 
purposes;
    (ii) The publication date of EPA's approval of such a budget in the 
Federal Register; or
    (iii) The effective date of EPA's approval of such a budget in the 
Federal Register, if such approval is completed through direct final 
rulemaking.
    (2) In NO2 nonattainment areas the interim emissions 
tests must be satisfied as required by Sec.  93.119 for conformity 
determinations made when there is no approved motor vehicle emissions 
budget from an applicable implementation plan and no adequate motor 
vehicle emissions budget from a submitted control strategy 
implementation plan revision or maintenance plan.
    (i) PM 2.5 nonattainment and maintenance areas. In addition to the 
criteria listed in Table 1 in paragraph (b) of this section that are 
required to be satisfied at all times, in PM2.5 
nonattainment and maintenance areas conformity determinations must 
include a demonstration that the budget and/or interim emissions tests 
are satisfied as described in the following:
    (1) In PM2.5 nonattainment and maintenance areas the 
budget test must be satisfied as required by Sec.  93.118 for 
conformity determinations made on or after:
    (i) The effective date of EPA's finding that a motor vehicle 
emissions budget in a submitted control strategy implementation plan 
revision or maintenance plan is adequate for transportation conformity 
purposes;
    (ii) The publication date of EPA's approval of such a budget in the 
Federal Register; or
    (iii) The effective date of EPA's approval of such a budget in the 
Federal Register, if such approval is completed through direct final 
rulemaking.
    (2) In PM2.5 nonattainment areas the interim emissions 
tests must be satisfied as required by Sec.  93.119 for conformity 
determinations made if there is no approved motor vehicle emissions 
budget from an applicable implementation plan and no adequate motor 
vehicle emissions budget from a submitted control strategy 
implementation plan revision or maintenance plan.
    (j) Areas with limited maintenance plans. Notwithstanding the other 
paragraphs of this section, an area is not required to satisfy the 
regional emissions analysis for Sec.  93.118 and/or Sec.  93.119 for a 
given pollutant and NAAQS, if the area has an adequate or approved 
limited maintenance plan for such pollutant and NAAQS. A limited 
maintenance plan would have to demonstrate that it would be 
unreasonable to expect that such an area would experience enough motor 
vehicle emissions growth for a NAAQS violation to occur. A conformity 
determination that meets other applicable criteria in Table 1 of 
paragraph (b) of this section is still required, including the hot-spot 
requirements for projects in CO and PM10 areas.
    (k) Areas with insignificant motor vehicle emissions. 
Notwithstanding the other paragraphs in this section, an area is not 
required to satisfy a regional emissions analysis for Sec.  93.118 and/
or Sec.  93.119 for a given pollutant/precursor and NAAQS, if EPA finds 
through the adequacy or approval process that a SIP demonstrates that 
regional motor vehicle emissions are an insignificant contributor to 
the air quality problem for that pollutant/precursor and NAAQS. The SIP 
would have to demonstrate that it would be unreasonable to expect that 
such an area would experience enough motor vehicle emissions growth in 
that pollutant/precursor for a NAAQS violation to occur. Such a finding 
would be based on a number of factors, including the percentage of 
motor vehicle emissions in the context of the total SIP inventory, the 
current state of air quality as determined by monitoring data for that 
NAAQS, the absence of SIP motor vehicle control measures, and 
historical trends and future projections of the growth of motor vehicle 
emissions. A conformity determination that meets other applicable 
criteria in Table 1 of paragraph (b) of this section is still required, 
including regional emissions analyses for Sec.  93.118 and/or Sec.  
93.119 for other pollutants/precursors and NAAQS that apply. Hot-spot 
requirements for projects in CO and PM10 areas in Sec.  
93.116 must also be satisfied, unless EPA determines that the SIP also 
demonstrates that projects will not create new localized violations 
and/or increase the severity or number of existing violations of such 
NAAQS. If EPA subsequently finds that motor vehicle emissions of a 
given pollutant/precursor are significant, this paragraph would no 
longer apply for future conformity determinations for that pollutant/
precursor and NAAQS.
    (l) * * *
    (2) Isolated rural nonattainment and maintenance areas are subject 
to the budget and/or interim emissions tests as described in paragraphs 
(c) through (k) of this section, with the following modifications:
* * * * *

0
8. Section 93.110(a) is revised to read as follows:


Sec.  93.110  Criteria and procedures: Latest planning assumptions.

    (a) Except as provided in this paragraph, the conformity 
determination, with respect to all other applicable criteria in 
Sec. Sec.  93.111 through 93.119, must be based upon the most recent 
planning assumptions in force at the time the conformity analysis 
begins. The conformity determination must satisfy the requirements of 
paragraphs (b) through (f) of this section using the planning 
assumptions available at the time the conformity analysis begins as 
determined through the interagency consultation process required in 
Sec.  93.105(c)(1)(i). The ``time the conformity analysis begins'' for 
a transportation plan or TIP determination is the point at which the 
MPO or other designated agency begins to model the impact of the 
proposed transportation plan or TIP on travel and/or emissions. New 
data that becomes available after an analysis begins is required to be 
used in the conformity determination only if a significant delay in the 
analysis has occurred, as determined through interagency consultation.
* * * * *

0
9. Section 93.116 is revised to read as follows:


Sec.  93.116  Criteria and procedures: Localized CO and PM10 
violations (hot spots).

    (a) This paragraph applies at all times. The FHWA/FTA project must 
not cause or contribute to any new localized CO

[[Page 40078]]

or PM10 violations or increase the frequency or severity of 
any existing CO or PM10 violations in CO and PM10 
nonattainment and maintenance areas. This criterion is satisfied if it 
is demonstrated that during the time frame of the transportation plan 
(or regional emissions analysis) no new local violations will be 
created and the severity or number of existing violations will not be 
increased as a result of the project. The demonstration must be 
performed according to the consultation requirements of Sec.  
93.105(c)(1)(i) and the methodology requirements of Sec.  93.123.
    (b) This paragraph applies for CO nonattainment areas as described 
in Sec.  93.109(f)(1). Each FHWA/FTA project must eliminate or reduce 
the severity and number of localized CO violations in the area 
substantially affected by the project (in CO nonattainment areas). This 
criterion is satisfied with respect to existing localized CO violations 
if it is demonstrated that during the time frame of the transportation 
plan (or regional emissions analysis) existing localized CO violations 
will be eliminated or reduced in severity and number as a result of the 
project. The demonstration must be performed according to the 
consultation requirements of Sec.  93.105(c)(1)(i) and the methodology 
requirements of Sec.  93.123.

0
10. Section 93.117 is revised to read as follows:


Sec.  93.117  Criteria and procedures: Compliance with PM10 
and PM2.5 control measures.

    The FHWA/FTA project must comply with any PM10 and 
PM2.5 control measures in the applicable implementation 
plan. This criterion is satisfied if the project-level conformity 
determination contains a written commitment from the project sponsor to 
include in the final plans, specifications, and estimates for the 
project those control measures (for the purpose of limiting 
PM10 and PM2.5 emissions from the construction 
activities and/or normal use and operation associated with the project) 
that are contained in the applicable implementation plan.

0
11. Section 93.118 is amended by:
0
a. Revising the reference ``Sec.  93.109(c) through (g)'' in paragraph 
(a) to read ``Sec.  93.109(c) through (l)'';
0
b. Revising paragraphs (b) introductory text and (b)(2)(iii), adding 
paragraph (b)(2)(iv), and removing the word ``and'' at the end of 
paragraph (b)(2)(ii);
0
c. Revising paragraphs (e)(1), (e)(2) and (e)(3); and
0
d. Adding new paragraph (f).
    The revisions and additions read as follows:


Sec.  93.118  Criteria and procedures: Motor vehicle emissions budget.

* * * * *
    (b) Consistency with the motor vehicle emissions budget(s) must be 
demonstrated for each year for which the applicable (and/or submitted) 
implementation plan specifically establishes motor vehicle emissions 
budget(s), for the attainment year (if it is within the timeframe of 
the transportation plan), for the last year of the transportation 
plan's forecast period, and for any intermediate years as necessary so 
that the years for which consistency is demonstrated are no more than 
ten years apart, as follows:
* * * * *
    (2) * * *
    (iii) If an approved and/or submitted control strategy 
implementation plan has established motor vehicle emissions budgets for 
years in the time frame of the transportation plan, emissions in these 
years must be less than or equal to the control strategy implementation 
plan's motor vehicle emissions budget(s) for these years; and
    (iv) For any analysis years before the last year of the maintenance 
plan, emissions must be less than or equal to the motor vehicle 
emissions budget(s) established for the most recent prior year.
* * * * *
    (e) * * *
    (1) Consistency with the motor vehicle emissions budgets in 
submitted control strategy implementation plan revisions or maintenance 
plans must be demonstrated if EPA has declared the motor vehicle 
emissions budget(s) adequate for transportation conformity purposes, 
and the adequacy finding is effective. However, motor vehicle emissions 
budgets in submitted implementation plans do not supersede the motor 
vehicle emissions budgets in approved implementation plans for the same 
Clean Air Act requirement and the period of years addressed by the 
previously approved implementation plan, unless EPA specifies otherwise 
in its approval of a SIP.
    (2) If EPA has not declared an implementation plan submission's 
motor vehicle emissions budget(s) adequate for transportation 
conformity purposes, the budget(s) shall not be used to satisfy the 
requirements of this section. Consistency with the previously 
established motor vehicle emissions budget(s) must be demonstrated. If 
there are no previously approved implementation plans or implementation 
plan submissions with adequate motor vehicle emissions budgets, the 
interim emissions tests required by Sec.  93.119 must be satisfied.
    (3) If EPA declares an implementation plan submission's motor 
vehicle emissions budget(s) inadequate for transportation conformity 
purposes after EPA had previously found the budget(s) adequate, and 
conformity of a transportation plan or TIP has already been determined 
by DOT using the budget(s), the conformity determination will remain 
valid. Projects included in that transportation plan or TIP could still 
satisfy Sec. Sec.  93.114 and 93.115, which require a currently 
conforming transportation plan and TIP to be in place at the time of a 
project's conformity determination and that projects come from a 
conforming transportation plan and TIP.
* * * * *
    (f) Adequacy review process for implementation plan submissions. 
EPA will use the procedure listed in paragraph (f)(1) or (f)(2) of this 
section to review the adequacy of an implementation plan submission:
    (1) When EPA reviews the adequacy of an implementation plan 
submission prior to EPA's final action on the implementation plan,
    (i) EPA will notify the public through EPA's website when EPA 
receives an implementation plan submission that will be reviewed for 
adequacy.
    (ii) The public will have a minimum of 30 days to comment on the 
adequacy of the implementation plan submission. If the complete 
implementation plan is not accessible electronically through the 
internet and a copy is requested within 15 days of the date of the 
website notice, the comment period will be extended for 30 days from 
the date that a copy of the implementation plan is mailed.
    (iii) After the public comment period closes, EPA will inform the 
State in writing whether EPA has found the submission adequate or 
inadequate for use in transportation conformity, including response to 
any comments submitted directly and review of comments submitted 
through the State process, or EPA will include the determination of 
adequacy or inadequacy in a proposed or final action approving or 
disapproving the implementation plan under paragraph (f)(2)(iii) of 
this section.
    (iv) EPA will publish a Federal Register notice to inform the 
public of EPA's finding. If EPA finds the submission adequate, the 
effective date of this finding will be 15 days from the date the notice 
is published as established in the Federal Register notice, unless EPA 
is taking a final approval action on the SIP as described in paragraph 
(f)(2)(iii) of this section.
    (v) EPA will announce whether the implementation plan submission is

[[Page 40079]]

adequate or inadequate for use in transportation conformity on EPA's 
website. The website will also include EPA's response to comments if 
any comments were received during the public comment period.
    (vi) If after EPA has found a submission adequate, EPA has cause to 
reconsider this finding, EPA will repeat actions described in 
paragraphs (f)(1)(i) through (v) or (f)(2) of this section unless EPA 
determines that there is no need for additional public comment given 
the deficiencies of the implementation plan submission. In all cases 
where EPA reverses its previous finding to a finding of inadequacy 
under paragraph (f)(1) of this section, such a finding will become 
effective immediately upon the date of EPA's letter to the State.
    (vii) If after EPA has found a submission inadequate, EPA has cause 
to reconsider the adequacy of that budget, EPA will repeat actions 
described in paragraphs (f)(1)(i) through (v) or (f)(2) of this 
section.
    (2) When EPA reviews the adequacy of an implementation plan 
submission simultaneously with EPA's approval or disapproval of the 
implementation plan,
    (i) EPA's Federal Register notice of proposed or direct final 
rulemaking will serve to notify the public that EPA will be reviewing 
the implementation plan submission for adequacy.
    (ii) The publication of the notice of proposed rulemaking will 
start a public comment period of at least 30 days.
    (iii) EPA will indicate whether the implementation plan submission 
is adequate and thus can be used for conformity either in EPA's final 
rulemaking or through the process described in paragraphs (f)(1)(iii) 
through (v) of this section. If EPA makes an adequacy finding through a 
final rulemaking that approves the implementation plan submission, such 
a finding will become effective upon the publication date of EPA's 
approval in the Federal Register, or upon the effective date of EPA's 
approval if such action is conducted through direct final rulemaking. 
EPA will respond to comments received directly and review comments 
submitted through the State process and include the response to 
comments in the applicable docket.
0
12. Section 93.119 is amended by:
0
a. Revising the section heading and paragraphs (a) and (b);
0
b. Redesignating paragraphs (c), (d), (e), (f), (g) and (h) as 
paragraphs (d), (f), (g), (h), (i) and (j);
0
c. Adding new paragraphs (c) and (e);
0
d. Revising newly redesignated paragraphs (d) introductory text and 
(d)(1);
0
e. Revising newly redesignated paragraph (f)(5), removing the period at 
the end of newly redesignated paragraph (f)(6) and adding a semicolon 
in its place, and adding new paragraphs (f)(7) and (f)(8);
0
f. Revising newly redesignated paragraph (g);
0
g. In newly redesignated paragraphs (h) introductory text and (i) 
introductory text, revising the reference ``paragraphs (b) and (c)'' to 
read ``paragraphs (b) through (e)''; and,
0
h. In newly redesignated paragraph (j), revising the reference 
``paragraphs (b) and (c)'' to read ``paragraphs (b) through (e)''.
    The revisions and additions read as follows:


Sec.  93.119  Criteria and procedures: Interim emissions in areas 
without motor vehicle emissions budgets.

    (a) The transportation plan, TIP, and project not from a conforming 
transportation plan and TIP must satisfy the interim emissions test(s) 
as described in Sec.  93.109(c) through (l). This criterion applies to 
the net effect of the action (transportation plan, TIP, or project not 
from a conforming plan and TIP) on motor vehicle emissions from the 
entire transportation system.
    (b) Ozone areas. The requirements of this paragraph apply to all 1-
hour ozone and 8-hour ozone NAAQS areas, except for certain 
requirements as indicated. This criterion may be met:
    (1) In moderate and above ozone nonattainment areas that are 
subject to the reasonable further progress requirements of CAA section 
182(b)(1) if a regional emissions analysis that satisfies the 
requirements of Sec.  93.122 and paragraphs (g) through (j) of this 
section demonstrates that for each analysis year and for each of the 
pollutants described in paragraph (f) of this section:
    (i) The emissions predicted in the ``Action'' scenario are less 
than the emissions predicted in the ``Baseline'' scenario, and this can 
be reasonably expected to be true in the periods between the analysis 
years; and
    (ii) The emissions predicted in the ``Action'' scenario are lower 
than:
    (A) 1990 emissions by any nonzero amount, in areas for the 1-hour 
ozone NAAQS as described in Sec.  93.109(c); or
    (B) 2002 emissions by any nonzero amount, in areas for the 8-hour 
ozone NAAQS as described in Sec.  93.109(d) and (e).
    (2) In marginal and below ozone nonattainment areas and other ozone 
nonattainment areas that are not subject to the reasonable further 
progress requirements of CAA section 182(b)(1) if a regional emissions 
analysis that satisfies the requirements of Sec.  93.122 and paragraphs 
(g) through (j) of this section demonstrates that for each analysis 
year and for each of the pollutants described in paragraph (f) of this 
section:
    (i) The emissions predicted in the ``Action'' scenario are not 
greater than the emissions predicted in the ``Baseline'' scenario, and 
this can be reasonably expected to be true in the periods between the 
analysis years; or
    (ii) The emissions predicted in the ``Action'' scenario are not 
greater than:
    (A) 1990 emissions, in areas for the 1-hour ozone NAAQS as 
described in Sec.  93.109(c); or
    (B) 2002 emissions, in areas for the 8-hour ozone NAAQS as 
described in Sec.  93.109(d) and (e).
    (c) CO areas. This criterion may be met:
    (1) In moderate areas with design value greater than 12.7 ppm and 
serious CO nonattainment areas that are subject to CAA section 
187(a)(7) if a regional emissions analysis that satisfies the 
requirements of Sec.  93.122 and paragraphs (g) through (j) of this 
section demonstrates that for each analysis year and for each of the 
pollutants described in paragraph (f) of this section:
    (i) The emissions predicted in the ``Action'' scenario are less 
than the emissions predicted in the ``Baseline'' scenario, and this can 
be reasonably expected to be true in the periods between the analysis 
years; and
    (ii) The emissions predicted in the ``Action'' scenario are lower 
than 1990 emissions by any nonzero amount.
    (2) In moderate areas with design value less than 12.7 ppm and not 
classified CO nonattainment areas if a regional emissions analysis that 
satisfies the requirements of Sec.  93.122 and paragraphs (g) through 
(j) of this section demonstrates that for each analysis year and for 
each of the pollutants described in paragraph (f) of this section:
    (i) The emissions predicted in the ``Action'' scenario are not 
greater than the emissions predicted in the ``Baseline'' scenario, and 
this can be reasonably expected to be true in the periods between the 
analysis years; or
    (ii) The emissions predicted in the ``Action'' scenario are not 
greater than 1990 emissions.
    (d) PM10 and NO2 areas. This criterion may be met in 
PM10 and NO2 nonattainment areas if a regional 
emissions analysis that satisfies the requirements of Sec.  93.122 and 
paragraphs (g) through (j) of this section demonstrates that for each 
analysis year and for each of the pollutants described

[[Page 40080]]

in paragraph (f) of this section, one of the following requirements is 
met:
    (1) The emissions predicted in the ``Action'' scenario are not 
greater than the emissions predicted in the ``Baseline'' scenario, and 
this can be reasonably expected to be true in the periods between the 
analysis years; or
* * * * *
    (e) PM2.5 areas. This criterion may be met in PM2.5 
nonattainment areas if a regional emissions analysis that satisfies the 
requirements of Sec.  93.122 and paragraphs (g) through (j) of this 
section demonstrates that for each analysis year and for each of the 
pollutants described in paragraph (f) of this section, one of the 
following requirements is met:
    (1) The emissions predicted in the ``Action'' scenario are not 
greater than the emissions predicted in the ``Baseline'' scenario, and 
this can be reasonably expected to be true in the periods between the 
analysis years; or
    (2) The emissions predicted in the ``Action'' scenario are not 
greater than 2002 emissions.
    (f) * * *
    (5) VOC and/or NOx in PM10 areas if the EPA 
Regional Administrator or the director of the State air agency has made 
a finding that one or both of such precursor emissions from within the 
area are a significant contributor to the PM10 nonattainment 
problem and has so notified the MPO and DOT;
    (6) * * *
    (7) PM2.5 in PM2.5 areas; and
    (8) Reentrained road dust in PM2.5 areas only if the EPA 
Regional Administrator or the director of the State air agency has made 
a finding that emissions from reentrained road dust within the area are 
a significant contributor to the PM2.5 nonattainment problem 
and has so notified the MPO and DOT.
    (g) Analysis years. (1) The regional emissions analysis must be 
performed for analysis years that are no more than ten years apart. The 
first analysis year must be no more than five years beyond the year in 
which the conformity determination is being made. The last year of the 
transportation plan's forecast period must also be an analysis year.
    (2) For areas using paragraphs (b)(2)(i), (c)(2)(i), (d)(1), and 
(e)(1) of this section, a regional emissions analysis that satisfies 
the requirements of Sec.  93.122 and paragraphs (g) through (j) of this 
section would not be required for analysis years in which the 
transportation projects and planning assumptions in the ``Action'' and 
``Baseline'' scenarios are exactly the same. In such a case, paragraph 
(a) of this section can be satisfied by documenting that the 
transportation projects and planning assumptions in both scenarios are 
exactly the same, and consequently, the emissions predicted in the 
``Action'' scenario are not greater than the emissions predicted in the 
``Baseline'' scenario for such analysis years.
* * * * *

0
13. Section 93.120 is amended by revising paragraph (a)(2) to read as 
follows:


Sec.  93.120  Consequences of control strategy implementation plan 
failures.

    (a) * * *
    (2) If EPA disapproves a submitted control strategy implementation 
plan revision without making a protective finding, only projects in the 
first three years of the currently conforming transportation plan and 
TIP may be found to conform. This means that beginning on the effective 
date of a disapproval without a protective finding, no transportation 
plan, TIP, or project not in the first three years of the currently 
conforming transportation plan and TIP may be found to conform until 
another control strategy implementation plan revision fulfilling the 
same CAA requirements is submitted, EPA finds its motor vehicle 
emissions budget(s) adequate pursuant to Sec.  93.118 or approves the 
submission, and conformity to the implementation plan revision is 
determined.
* * * * *

0
14. Section 93.121 is amended by:
0
a. Revising paragraph (a)(1), redesignating paragraph (a)(2) as (a)(3), 
adding a new paragraph (a)(2) and revising newly redesignated paragraph 
(a)(3);
0
b. Amending paragraph (b) introductory text by removing the reference 
``Sec.  93.109(g)'' and adding in its place a reference for ``Sec.  
93.109(l)'', and revising paragraph (b)(1); and
0
c. Adding new paragraph (c).
    The revisions and additions read as follows:


Sec.  93.121  Requirements for adoption or approval of projects by 
other recipients of funds designated under title 23 U.S.C. or the 
Federal Transit Laws.

    (a) * * *
    (1) The project comes from the currently conforming transportation 
plan and TIP, and the project's design concept and scope have not 
changed significantly from those which were included in the regional 
emissions analysis for that transportation plan and TIP;
    (2) The project is included in the regional emissions analysis for 
the currently conforming transportation plan and TIP conformity 
determination (even if the project is not strictly included in the 
transportation plan or TIP for the purpose of MPO project selection or 
endorsement) and the project's design concept and scope have not 
changed significantly from those which were included in the regional 
emissions analysis; or
    (3) A new regional emissions analysis including the project and the 
currently conforming transportation plan and TIP demonstrates that the 
transportation plan and TIP would still conform if the project were 
implemented (consistent with the requirements of Sec. Sec.  93.118 and/
or 93.119 for a project not from a conforming transportation plan and 
TIP).
    (b) * * *
    (1) The project was included in the regional emissions analysis 
supporting the most recent conformity determination that reflects the 
portion of the statewide transportation plan and statewide TIP which 
are in the nonattainment or maintenance area, and the project's design 
concept and scope has not changed significantly; or
* * * * *
    (c) Notwithstanding paragraphs (a) and (b) of this section, in 
nonattainment and maintenance areas subject to Sec.  93.109(j) or (k) 
for a given pollutant/precursor and NAAQS, no recipient of Federal 
funds designated under title 23 U.S.C. or the Federal Transit Laws 
shall adopt or approve a regionally significant highway or transit 
project, regardless of funding source, unless the recipient finds that 
the requirements of one of the following are met for that pollutant/
precursor and NAAQS:
    (1) The project was included in the most recent conformity 
determination for the transportation plan and TIP and the project's 
design concept and scope has not changed significantly; or
    (2) The project was included in the most recent conformity 
determination that reflects the portion of the statewide transportation 
plan and statewide TIP which are in the nonattainment or maintenance 
area, and the project's design concept and scope has not changed 
significantly.

0
15. Section 93.122 is amended by:
0
(a) Redesignating paragraphs (c), (d), and (e) as paragraphs (d), (e) 
and (g), respectively;
0
(b) Adding new paragraphs (c) and (f); and
0
(c) Revising newly redesignated paragraphs (g)(1) and (g)(2) 
introductory text, and adding new paragraph (g)(3).
    The revisions and additions read as follows:

[[Page 40081]]

Sec.  93.122  Procedures for determining regional transportation-
related emissions.

* * * * *
    (c) Two-year grace period for regional emissions analysis 
requirements in certain ozone and CO areas. The requirements of 
paragraph (b) of this section apply to such areas or portions of such 
areas that have not previously been required to meet these requirements 
for any existing NAAQS two years from the following:
    (1) The effective date of EPA's reclassification of an ozone or CO 
nonattainment area that has an urbanized area population greater than 
200,000 to serious or above;
    (2) The official notice by the Census Bureau that determines the 
urbanized area population of a serious or above ozone or CO 
nonattainment area to be greater than 200,000; or,
    (3) The effective date of EPA's action that classifies a newly 
designated ozone or CO nonattainment area that has an urbanized area 
population greater than 200,000 as serious or above.
* * * * *
    (f) PM2.5 from construction-related fugitive dust. (1) For 
PM2.5 areas in which the implementation plan does not 
identify construction-related fugitive PM2.5 as a 
significant contributor to the nonattainment problem, the fugitive 
PM2.5 emissions associated with highway and transit project 
construction are not required to be considered in the regional 
emissions analysis.
    (2) In PM2.5 nonattainment and maintenance areas with 
implementation plans which identify construction-related fugitive 
PM2.5 as a significant contributor to the nonattainment 
problem, the regional PM2.5 emissions analysis shall 
consider construction-related fugitive PM2.5 and shall 
account for the level of construction activity, the fugitive 
PM2.5 control measures in the applicable implementation 
plan, and the dust-producing capacity of the proposed activities.
    (g) * * *
    (1) Conformity determinations for a new transportation plan and/or 
TIP may be demonstrated to satisfy the requirements of Sec. Sec.  
93.118 (``Motor vehicle emissions budget'') or 93.119 (``Interim 
emissions in areas without motor vehicle emissions budgets'') without 
new regional emissions analysis if the previous regional emissions 
analysis also applies to the new plan and/or TIP. This requires a 
demonstration that:
    (i) The new plan and/or TIP contain all projects which must be 
started in the plan and TIP's timeframes in order to achieve the 
highway and transit system envisioned by the transportation plan;
    (ii) All plan and TIP projects which are regionally significant are 
included in the transportation plan with design concept and scope 
adequate to determine their contribution to the transportation plan's 
and/or TIP's regional emissions at the time of the previous conformity 
determination;
    (iii) The design concept and scope of each regionally significant 
project in the new plan and/or TIP are not significantly different from 
that described in the previous transportation plan; and
    (iv) The previous regional emissions analysis is consistent with 
the requirements of Sec. Sec.  93.118 (including that conformity to all 
currently applicable budgets is demonstrated) and/or 93.119, as 
applicable.
    (2) A project which is not from a conforming transportation plan 
and a conforming TIP may be demonstrated to satisfy the requirements of 
Sec.  93.118 or Sec.  93.119 without additional regional emissions 
analysis if allocating funds to the project will not delay the 
implementation of projects in the transportation plan or TIP which are 
necessary to achieve the highway and transit system envisioned by the 
transportation plan, the previous regional emissions analysis is still 
consistent with the requirements of Sec.  93.118 (including that 
conformity to all currently applicable budgets is demonstrated) and/or 
Sec.  93.119, as applicable, and if the project is either:
* * * * *
    (3) A conformity determination that relies on paragraph (g) of this 
section does not satisfy the frequency requirements of Sec.  93.104(b) 
or (c).


Sec.  93.124  [Amended]

0
16. Section 93.124 is amended by removing paragraph (b) and 
redesignating paragraphs (c) through (e) as paragraphs (b) through (d).


Sec.  93.125  [Amended]

0
17. In Sec.  93.125, paragraph (a) is amended by revising the reference 
``93.119 (``Emissions reductions in areas without motor vehicle 
emissions budgets'')'' to read ``93.119 (``Interim emissions in areas 
without motor vehicle emissions budgets''),'' and paragraph (d) is 
amended by revising the phrase ``emission reduction requirements of 
Sec.  93.119'' to read ``interim emissions requirements of Sec.  
93.119.''


Sec.  93.126  [Amended]

0
18. In Sec.  93.126, Table 2 is amended under the heading ``Other'' by 
revising the entry for ``Emergency or hardship advance land 
acquisitions (23 CFR 712.204(d))'' to read ``Emergency or hardship 
advance land acquisitions (23 CFR 710.503).''

[FR Doc. 04-14213 Filed 6-30-04; 8:45 am]
BILLING CODE 6560-50-P