Document ID: EPA-HQ-OAR-2008-0540-0036
Agency: epa
Document Type: Rule
Title: Transportation Conformity Rule PM2.5 and PM10 Amendments
Posted Date: 2010-03-24T04:00Z

[Federal Register: March 24, 2010 (Volume 75, Number 56)]
[Rules and Regulations]               
[Page 14259-14285]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24mr10-14]                         

[[Page 14259]]

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Part II

Environmental Protection Agency

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40 CFR Part 93

Transportation Conformity Rule PM2.5 and PM10 Amendments; Final Rule

[[Page 14260]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 93

[EPA-HQ-OAR-2008-0540; FRL-9127-7]
RIN 2060-AP29

 
Transportation Conformity Rule PM2.5 and 
PM10 Amendments

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: In this action, EPA is amending the transportation conformity 
rule to finalize provisions that were proposed on May 15, 2009. These 
amendments primarily affect conformity's implementation in 
PM2.5 and PM10 nonattainment and maintenance 
areas. EPA is updating the transportation conformity regulation in 
light of an October 17, 2006 final rule that strengthened the 24-hour 
PM2.5 national ambient air quality standard (NAAQS) and 
revoked the annual PM10 NAAQS. In addition, EPA is 
clarifying the regulations concerning hot-spot analyses to address a 
December 2007 remand from the Court of Appeals for the District of 
Columbia Circuit. This portion of the final rule applies to 
PM2.5 and PM10 nonattainment and maintenance 
areas as well as carbon monoxide nonattainment and maintenance areas.
    The Clean Air Act (CAA) requires federally supported transportation 
plans, transportation improvement programs, and projects to be 
consistent with (``conform to'') the purpose of the state air quality 
implementation plan. The U.S. Department of Transportation (DOT) is 
EPA's federal partner in implementing the transportation conformity 
regulation. EPA has consulted with DOT, and they concur with this final 
rule.

DATES: This final rule is effective on April 23, 2010.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2008-0540. All documents in the docket are listed on the 
http://www.regulations.gov Web site. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, is not placed on the Internet and will be 
publicly available only in hard copy form. Publicly available docket 
materials are available either electronically through http://
www.regulations.gov or in hard copy at the Air and Radiation Docket, 
EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, 
DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday 
through Friday, excluding legal holidays. The telephone number for the 
Public Reading Room is (202) 566-1744 and the telephone number for the 
Air and Radiation Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Laura Berry, State Measures and 
Conformity Group, Transportation and Regional Programs Division, 
Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 
48105, e-mail address: berry.laura@epa.gov, telephone number: (734) 
214-4858, fax number: (734) 214-4052; or Patty Klavon, State Measures 
and Conformity Group, Transportation and Regional Programs Division, 
Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 
48105, e-mail address: klavon.patty@epa.gov, telephone number: (734) 
214-4476, fax number: (734) 214-4052.

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

I. General Information
II. Background on the Transportation Conformity Rule
III. General Overview of Transportation Conformity for the 2006 
PM2.5 NAAQS
IV. Baseline Year for Certain 2006 PM2.5 Nonattainment 
Areas
V. Regional Conformity Tests in 2006 PM2.5 Nonattainment 
Areas That Do Not Have Adequate or Approved SIP Budgets for the 1997 
PM2.5 NAAQS
VI. Regional Conformity Tests in 2006 PM2.5 Areas That 
Have 1997 PM2.5 SIP Budgets
VII. Other Conformity Requirements for 2006 PM2.5 Areas
VIII. Transportation Conformity in PM10 Nonattainment and 
Maintenance Areas and the Revocation of the Annual PM10 
NAAQS
IX. Response to the December 2007 Hot-Spot Court Decision
X. Statutory and Executive Order Reviews

I. General Information

A. Does This Action Apply to Me?

    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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                             Category                                      Examples of regulated 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 transportation 
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 40 CFR 93.102. 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 an official public docket for this action under 
Docket ID No. EPA-HQ-OAR-2008-0540. You can get a paper copy of this 
Federal Register document, as well as the documents specifically 
referenced in this action, any public comments received, and other 
information related to this action at the official public docket. See 
the ADDRESSES section for its location.
2. Electronic Access
    You may access this Federal Register document electronically 
through EPA's Transportation Conformity Web site at http://www.epa.gov/
otaq/stateresources/transconf/index.htm. You may also access this 
document electronically under the Federal Register listings at http://
www.epa.gov/fedrgstr/.
    An electronic version of the official public docket is available 
through http://www.regulations.gov. You may use http://
www.regulations.gov to view public comments, access the index listing 
of the contents of the official

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public docket, and access those documents in the public docket that are 
available electronically. Once in the system, select ``search,'' then 
key in the appropriate docket identification number.
    Certain types of information will not be placed in the electronic 
public docket. Information claimed as CBI and other information for 
which disclosure is restricted by statute is not available for public 
viewing in the electronic public docket. EPA's policy is that 
copyrighted material is not placed in the electronic public docket but 
is available only in printed, paper form in the official public docket.
    To the extent feasible, publicly available docket materials will be 
made available in the electronic public docket. When a document is 
selected from the index list in EPA Dockets, the system will identify 
whether the document is available for viewing in the electronic public 
docket. 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 the 
ADDRESSES section. EPA intends to provide electronic access in the 
future to all of the publicly available docket materials through the 
electronic public docket.
    For additional information about the electronic public docket, 
visit the EPA Docket Center homepage at http://www.epa.gov/epahome/
dockets.htm.

II. Background on the Transportation Conformity Rule

A. What Is Transportation Conformity?

    Transportation conformity is required under CAA section 176(c) (42 
U.S.C. 7506(c)) to ensure that transportation plans, transportation 
improvement programs (TIPs) and federally supported highway and transit 
project activities are consistent with (``conform to'') the purpose of 
the state air quality implementation plan (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 national ambient air quality standards 
(NAAQS) or any interim milestones.\1\ Transportation conformity applies 
to areas that are designated nonattainment, and those areas 
redesignated to attainment after 1990 (``maintenance areas'') for 
transportation-related criteria pollutants: Carbon monoxide (CO), 
ozone, nitrogen dioxide (NO2) and particulate matter 
(PM2.5, and PM10).\2\
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    \1\ These requirements are found in Clean Air Act section 
176(c)(B)(i), (ii), and (iii): ``That such activities will not cause 
or contribute to any new violation of any standard in any area; 
increase the frequency or severity of any existing violation of any 
standard in any area; or delay timely attainment of any standard or 
any required interim emissions reductions or other milestones in any 
area.''
    \2\ 40 CFR 93.102(b)(1) defines PM2.5 and 
PM10 as particles with an aerodynamic diameter less than 
or equal to a nominal 2.5 and 10 micrometers, respectively.
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    EPA's transportation conformity rule (40 CFR Parts 51 and 93) 
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 several other amendments. DOT is EPA's federal 
partner in implementing the transportation conformity regulation. EPA 
has consulted with DOT, which concurs with this final rule.
    A few recent amendments to the transportation conformity rule are 
useful background for today's final rule. In a final rule EPA published 
on July 1, 2004 (69 FR 40004), EPA provided conformity procedures for 
state and local agencies under the 1997 8-hour ozone and 
PM2.5 national ambient air quality standards (NAAQS). EPA's 
nonattainment area designations for the 1997 8-hour ozone and 
PM2.5 NAAQS were effective in June 2004 and April 2005, 
respectively. The July 2004 update provided rules for implementing 
conformity for these NAAQS. In addition, on May 6, 2005, EPA 
promulgated a final rule entitled, ``Transportation Conformity Rule 
Amendments for the New PM2.5 National Ambient Air Quality 
Standard: PM2.5 Precursors'' (70 FR 24280). This final rule 
specified transportation-related PM2.5 precursors and when 
they must be considered in transportation conformity determinations in 
PM2.5 nonattainment and maintenance areas.
    On March 10, 2006, EPA promulgated a final rule (71 FR 12468) 
entitled, ``PM2.5 and PM10 Hot-Spot Analyses in 
Project-Level Transportation Conformity Determinations for the New 
PM2.5 and Existing PM10 National Ambient Air 
Quality Standards.'' This rule established the criteria and procedures 
for determining which transportation projects must be analyzed for 
local air quality impacts--or ``hot-spots''--in PM2.5 and 
PM10 nonattainment and maintenance areas. See Section IX. of 
today's preamble for more information regarding the March 2006 rule; 
see EPA's Web site at http://www.epa.gov/otaq/stateresources/transconf/
index.htm for further information about any of EPA's transportation 
conformity rulemakings.\3\
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    \3\ At this website, click on ``Regulations'' to find all of 
EPA's proposed and final rules as well as the current transportation 
conformity regulations.
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B. Why Are We Issuing This Final Rule?

    Today's action is necessary because EPA promulgated a final rule on 
October 17, 2006 that changed the PM2.5 and PM10 
NAAQS, as described further below. Today's action provides rules for 
implementing conformity for these revisions to the PM2.5 and 
PM10 NAAQS. Sections III. through VIII. describe the changes 
to the transportation conformity rule that are a result of the October 
2006 revisions to the PM2.5 and PM10 NAAQS.
    Today's final rule is the second transportation conformity 
rulemaking undertaken primarily for the purpose of addressing a new or 
revised NAAQS. Due to other statutory requirements, EPA will continue 
to establish new or revised NAAQS in the future. Therefore, EPA may 
consider restructuring certain sections of the conformity rule in a 
future rulemaking so that existing rule requirements would clearly 
apply to areas designated for future new or revised NAAQS, without 
having to update the rule each time a new or revised NAAQS is 
established.
    Note that in 2009, EPA issued an interim conformity guidance for 
areas designated nonattainment for the 2006 PM2.5 NAAQS \4\ 
(``2006 PM2.5 areas'').\5\ EPA issued this interim guidance 
to help new nonattainment areas meet conformity requirements by the end 
of the one-year grace period. While this interim guidance is superseded 
by today's final rule, conformity determinations done according to the 
interim guidance are consistent with the CAA, and with the 
transportation conformity rule.\6\ Therefore, conformity determinations 
based on the interim guidance and the transportation conformity rule in 
effect at the time of the conformity determination will remain valid. 
Conformity determinations completed on or after the effective date of 
this final rule must meet all the requirements in the final rule. EPA 
will work with the 2006 PM2.5

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areas to ensure they can meet conformity requirements on time.
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    \4\ ``2006 PM2.5 NAAQS'' refers to the 24-hour 
PM2.5 NAAQS promulgated in 2006.
    \5\ ``Interim Transportation Conformity Guidance for 2006 
PM2.5 Nonattainment Areas,'' EPA-420-B-09-036, November 
2009, available on EPA's Web site at: http://www.epa.gov/otaq/
stateresources/transconf/policy/420b09036.pdf.
    \6\ Today's final rule changes the baseline year used to 
demonstrate conformity for the 2006 PM2.5 NAAQS prior to 
having an adequate or approved PM2.5 SIP budget; the 
interim guidance addressed this change. Refer to Section IV. for 
further discussion of the baseline year for conformity purposes.
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    Today's final rule also responds to a court decision regarding the 
March 2006 hot-spot rulemaking. Section IX. of this preamble describes 
the issue, the court's decision, and EPA's response.

III. General Overview of Transportation Conformity for the 2006 
PM2.5 NAAQS

A. Background on 2006 PM2.5 NAAQS Development

    EPA issued a final rule on October 17, 2006, effective December 18, 
2006, that strengthened the 24-hour PM2.5 NAAQS and revoked 
the annual PM10 NAAQS (71 FR 61144). In that final rule, EPA 
strengthened the 24-hour PM2.5 NAAQS from the 1997 level of 
65 micrograms per cubic meter ([mu]g/m\3\) (average of 98th percentile 
values for three consecutive years) to 35 [mu]g/m\3\, while the level 
of the annual PM2.5 NAAQS remained unchanged at 15.0 
[micro]g/m\3\ (average of three consecutive annual average values). EPA 
selected levels for the final NAAQS after completing an extensive 
review of thousands of scientific studies on the impact of fine and 
coarse particles on public health and welfare. For additional 
information about the October 17, 2006 rulemaking, the final rule and 
EPA outreach materials can be found at: http://www.epa.gov/
pmdesignations/.
    The October 2006 rule establishing the 2006 PM2.5 NAAQS 
did not revoke the 1997 annual or 24-hour PM2.5 NAAQS. See 
Section III.D. below for details on how today's final rule interacts 
with conformity requirements for those areas designated nonattainment 
for the 1997 PM2.5 NAAQS.\7\
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    \7\ ``1997 PM2.5 NAAQS'' includes both the annual and 
the 24-hour 1997 PM2.5 NAAQS unless noted otherwise.
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    EPA signed the final rule designating areas for the 2006 
PM2.5 NAAQS on October 8, 2009.\8\ This final rule was 
published in the Federal Register on November 13, 2009, and became 
effective December 14, 2009. The designations for the 2006 
PM2.5 NAAQS are separate from the existing designations for 
the 1997 PM2.5 NAAQS.
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    \8\ A Federal Register notice designating areas for the 2006 
PM2.5 NAAQS had been signed in late December 2008 by 
then-Administrator Johnson, where the designations were based on air 
quality data from 2005-2007. The December 2008 notice was awaiting 
publication in January 2009 when the newly elected Administration 
identified the notice as one that should receive additional review 
before publication. However, this notice was never published in the 
Federal Register and, therefore, designations were not officially 
promulgated. CAA section 107(d)(2)(A) requires EPA to publish the 
notice in the Federal Register in order to promulgate designations. 
Since January 2009, monitoring data for 2008 has become available 
for areas across the U.S. Therefore, the final designations in the 
final rule signed by Administrator Jackson on October 8, 2009 are 
based on air quality monitoring data from Federal Reference Method 
monitors for calendar years 2006-2008.
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    However, in the final rule designating areas for the 2006 
PM2.5 NAAQS, EPA has also clarified that all 39 areas 
designated nonattainment for the 1997 PM2.5 NAAQS were 
violating the annual PM2.5 NAAQS, and two of those were also 
violating the 24-hour PM2.5 NAAQS.\9\ That is, EPA's 
designations rule clarifies that only two areas were designated 
nonattainment for the 1997 24-hour PM2.5 NAAQS, and that all 
39 nonattainment areas were designated nonattainment for the 1997 
annual PM2.5 NAAQS.
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    \9\ The two areas designated as nonattainment for both the 
annual and 24-hour 1997 PM2.5 NAAQS are the Los Angeles-
South Coast Air Basin, CA nonattainment area and the San Joaquin 
Valley, CA nonattainment area.
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    Transportation conformity applies for the NAAQS for which an area 
is designated nonattainment.\10\ Therefore, in two of the 1997 
PM2.5 areas, conformity applies for both the 1997 annual and 
24-hour NAAQS. In the other 37 1997 PM2.5 areas, conformity 
applies for the 1997 annual NAAQS, and not the 1997 24-hour 
PM2.5 NAAQS.
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    \10\ Clean Air Act section 176(c)(5) and 40 CFR 93.102(b).
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    Refer to EPA's Web site at: http://www.epa.gov/pmdesignations/
2006standards/index.htm for additional information about the 
nonattainment designations.

B. When Does Conformity Apply for the 2006 PM2.5 NAAQS?

    Transportation conformity for the 2006 PM2.5 NAAQS does 
not apply until December 14, 2010, which is one year after the 
effective date of nonattainment designations for this NAAQS. CAA 
section 176(c)(6) and 40 CFR 93.102(d) provide a one-year grace period 
from the effective date of designations before transportation 
conformity applies in areas newly designated nonattainment for a 
particular NAAQS.\11\
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    \11\ EPA began the process of notifying state and local 
agencies, via the EPA regional offices, of the timing of conformity 
under the 2006 PM2.5 NAAQS in its April 16, 2007 
memorandum entitled, ``Transportation Conformity and the Revised 24-
hour PM2.5 Standard,'' from Merrylin Zaw-Mon, Director, 
Transportation and Regional Programs Division, EPA Office of 
Transportation and Air Quality, to EPA Regional Air Directors, 
Regions I-X.
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    The following discussion provides more details on the application 
of the one-year grace period in different types of newly designated 
nonattainment areas for the 2006 PM2.5 NAAQS. This 
information is consistent with how conformity for new NAAQS has been 
implemented in the past.\12\ The conformity grace period will be 
available to all newly designated nonattainment areas for the 2006 
PM2.5 NAAQS.
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    \12\ See EPA's July 1, 2004 final rule for further background on 
how EPA has implemented this conformity grace period for the 1997 
PM2.5 NAAQS (69 FR 40004).
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    Metropolitan areas are urbanized areas that have a population 
greater than 50,000 and a designated metropolitan planning organization 
(MPO) responsible for transportation planning per 23 U.S.C. 134. Within 
one year after the effective date of the initial nonattainment 
designation for the 2006 PM2.5 NAAQS, a conformity 
determination for this NAAQS must be made by the MPO and DOT for the 
MPO's transportation plan and TIP. MPOs must continue to meet 
conformity requirements for any other applicable NAAQS, including the 
1997 PM2.5 NAAQS, if the area is designated nonattainment or 
maintenance for such NAAQS as well.
    In nonattainment and maintenance areas with a donut portion,\13\ 
adjacent MPOs must meet conformity requirements for the 2006 
PM2.5 NAAQS. The MPO must also continue to ensure that 
conformity is met for any other applicable NAAQS, including any 1997 
PM2.5 NAAQS for which the donut area is designated 
nonattainment.\14\ The interagency consultation partners for each newly 
designated nonattainment area that includes a donut portion should 
determine how best to consider the donut area transportation system and 
new donut area projects in the MPO's regional emissions analyses and 
transportation plan and TIP conformity determinations.
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    \13\ For the purposes of transportation conformity, a ``donut'' 
area is the geographic area outside a metropolitan planning area 
boundary, but inside a designated nonattainment or maintenance area 
boundary that includes an MPO (40 CFR 93.101). For more discussion 
on how conformity determinations should be made for donut areas, see 
the preamble to the July 1, 2004 conformity rule (69 FR 40013).
    \14\ Determining conformity for these other NAAQS during the 
one-year grace period is not necessary unless required by 40 CFR 
93.104 (for example, a new or amended transportation plan and TIP 
are to be adopted).
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    If, at the end of the one-year grace period, the MPO and DOT have 
not made a transportation plan and TIP conformity determination for the 
2006 PM2.5 NAAQS, the entire area, including any donut area, 
would be in a conformity ``lapse.'' \15\ During a

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conformity lapse, only certain projects can receive additional federal 
funding or approvals to proceed (e.g. exempt projects, project phases 
that were approved before the lapse).\16\ The practical impact of a 
conformity lapse will vary on an area-by-area basis.
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    \15\ The lapse grace period provision in CAA section 176(c)(9) 
does not apply to the deadline for newly designated nonattainment 
areas to make the initial transportation plan/TIP conformity 
determination within 12 months of the effective date of the 
nonattainment designation. For additional details on the conformity 
lapse grace period, see the preamble to the January 24, 2008 
conformity rule (73 FR 4423-4425).
    \16\ For additional information on projects that can proceed 
during a conformity lapse, refer to the final rule of July 1, 2004 
(69 FR 40005-40006), which addressed the March 2, 1999 U.S. Court of 
Appeals decision that affected related provisions of the conformity 
rule (Environmental Defense Fund v. EPA, 167 F.3d 641 (D.C. Cir. 
1999). See also the following guidance memoranda that address this 
court decision: DOT's January 2, 2002 guidance, published in the 
Federal Register on February 7, 2002 (67 FR 5882); DOT's May 20, 
2003 and FTA's April 9, 2003 supplemental guidance documents; and, 
EPA's May 14, 1999 guidance memorandum.
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    The one-year grace period for conformity also applies to project-
level conformity determinations (including hot-spot analyses in certain 
cases) in newly designated 2006 PM2.5 nonattainment areas. 
At the end of the one-year grace period for conformity, requirements 
for project-level conformity determinations must be met for the 2006 
PM2.5 NAAQS (including hot-spot analyses in certain cases) 
before any new federal approvals for such projects can occur. See Table 
1 in 40 CFR 93.109 for the conformity criteria that apply for project-
level conformity determinations.
    Isolated rural nonattainment and maintenance areas are areas that 
do not contain or are not part of any metropolitan planning area as 
designated by 23 U.S.C. 134 and 49 U.S.C. 5303 (40 CFR 93.101). As in 
other newly designated nonattainment areas, the one-year conformity 
grace period for the 2006 PM2.5 NAAQS will begin on the 
effective date of an isolated rural area's initial nonattainment 
designation. However, because these areas do not have federally 
required metropolitan transportation plans and TIPs, they are not 
subject to the frequency requirements for conformity determinations on 
transportation plans and TIPs (40 CFR 93.104(b),(c), and (e)). Instead, 
conformity determinations in isolated rural areas are required only 
when a non-exempt FHWA/FTA project(s) needs approval.
    Therefore, although the one-year conformity grace period is 
available to isolated rural areas, most likely no conformity 
consequences would occur upon the expiration date of the one-year grace 
period because these areas most likely would not have any projects that 
require federal funding or approval at that time. Once the conformity 
grace period has expired, a conformity determination would only be 
required in such areas when a non-exempt FHWA/FTA project needs 
approval. Conformity requirements for isolated rural areas can be found 
at 40 CFR 93.109(n).\17\
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    \17\ Prior to today's rulemaking, the requirements for isolated 
rural areas were found at Sec.  93.109(l). This section has been 
renamed as Sec.  93.109(n), as a result of other revisions and 
additions in this regulatory section. This is merely an 
administrative change and the conformity requirements for isolated 
rural areas remain unchanged.
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    Response to comments about the grace period. Some commenters 
believed that the one-year grace period would not allow enough time for 
some areas to meet the conformity requirements. These same commenters 
questioned whether a year would be enough time to adequately prepare 
attainment SIPs, learn EPA's new emissions factor model (called the 
Motor Vehicle Emissions Simulator, or MOVES model) when final, and 
complete their conformity determinations. To address these concerns, 
these commenters suggested lengthening the conformity grace period for 
newly designated nonattainment areas from one to two years.
    EPA understands that some areas, such as areas that have never done 
conformity before and multi-jurisdictional nonattainment areas (e.g., 
areas with multiple states and/or multiple MPOs) may have additional 
challenges in conducting their initial conformity determinations. 
However, the CAA 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.
    In accordance with the CAA, states were initially required to 
submit their recommendations for nonattainment areas based on monitored 
data by December 18, 2007, well before designations became 
effective.\18\ Additionally, EPA began the process of notifying state 
and local agencies, via the EPA regional offices, of the timing of 
conformity under the 2006 PM2.5 NAAQS in the April 16, 2007 
memorandum cited earlier.\19\ As mentioned, EPA provided interim 
guidance for the 2006 PM2.5 areas to assist in meeting 
conformity requirements by the end of the one-year grace period. 
Finally, EPA will be working with 2006 PM2.5 areas to 
provide technical assistance in an expeditious manner, such as helping 
each area determine which test applies for the first 2006 
PM2.5 conformity determination.
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    \18\ Information on 2006 PM2.5 nonattainment 
designations, including copies of EPA's designation letters, can be 
accessed from EPA's Web site at http://www.epa.gov/pmdesignations/
2006standards/state.htm.
    \19\ Memorandum entitled, ``Transportation Conformity and the 
Revised 24-hour PM2.5 Standard,'' from Merrylin Zaw-Mon, 
then-Director, Transportation and Regional Programs Division, EPA 
Office of Transportation and Air Quality, to EPA Regional Air 
Directors, Regions I- X, found on EPA's Web site at: http://
www.epa.gov/otaq/stateresources/transconf/generalinfo/rev24hr-
pm25.pdf.
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    We also want to clarify that while areas will have to complete a 
conformity determination for their transportation plans and TIPs within 
one year, they are not required to complete their attainment 
demonstration SIPs for the 2006 PM2.5 NAAQS in that same 
time period as the commenter suggested. Instead, they will have three 
years from the effective date of designations to submit their 
attainment demonstrations, per CAA section 172(b).
    Also, implementers will have additional time before MOVES is 
required for conformity determinations, as a different grace period 
will apply for MOVES once it is released. The conformity rule at 40 CFR 
93.111 provides a grace period before a new emissions model is required 
for conformity. This grace period can be anywhere from three months to 
two years depending on the degree of change from one model to another 
(40 CFR 93.111(b)(2)); EPA is intending to provide the maximum length 
two-year grace period for the transition to MOVES. Therefore, MOVES 
will not be required for the first transportation plan and TIP 
conformity determination done for the 2006 PM2.5 NAAQS. EPA 
will provide specific guidance regarding the MOVES grace period and 
when MOVES will be required to be used for SIPs and conformity. This 
guidance will be available on EPA's Web site at: http://www.epa.gov/
otaq/stateresources/transconf/policy.htm#models.
    EPA and DOT understand the concern that the commenter notes with 
respect to learning the new MOVES model, and therefore have devoted 
significant staff time and resources to training state and local air 
quality and transportation planners in using MOVES. During 2009, 20 
MOVES training sessions were held at locations across the U.S. Once 
MOVES is final, EPA intends to offer web-based training, and EPA and 
DOT are planning to hold additional in-person training sessions as 
well. See EPA's Web site: http://www.epa.gov/

[[Page 14264]]

otaq/models/moves/trainingsessions.htm for information about upcoming 
training sessions. Also note that other MOVES related guidance, 
including user guides and other technical information is available on 
EPA's Web site at: http://www.epa.gov/otaq/models/moves/index.htm and 
http://www.epa.gov/otaq/stateresources/transconf/policy.htm

C. Definitions for PM2.5 NAAQS

    EPA is adding two new definitions to Sec.  93.101 of the conformity 
rule to distinguish between the 1997 PM2.5 NAAQS and the 
2006 PM2.5 NAAQS. These definitions will help implement 
certain conformity requirements in areas that have been designated 
nonattainment for 1997 PM2.5 NAAQS and/or 2006 
PM2.5 NAAQS. Some areas designated nonattainment for the 
2006 PM2.5 NAAQS also are designated nonattainment for the 
1997 PM2.5 NAAQS. In addition, some areas are designated for 
only the 2006 PM2.5 NAAQS.
    These definitions are similar to the rule's definitions in 40 CFR 
93.101 for the 1-hour ozone NAAQS and 8-hour ozone NAAQS, and are 
generally consistent with how EPA is defining both kinds of 
PM2.5 areas for air quality planning purposes. EPA also 
notes that any provision of the conformity rule that references only 
``PM2.5'' and does not specify which PM2.5 NAAQS 
applies to any area designated nonattainment for a PM2.5 
NAAQS. EPA received no comments regarding these definitions.

D. How Does This Final Rule Interact With Conformity Requirements for 
the 1997 PM2.5 NAAQS?

    Sections IV. through VI. of today's final rule describe conformity 
requirements for areas designated nonattainment for the 2006 
PM2.5 NAAQS. No changes have been made to the existing 
transportation conformity requirements for areas designated 
nonattainment for the 1997 PM2.5 NAAQS.
    Nonattainment designations for the 1997 and 2006 PM2.5 
NAAQS are different designations with separate SIP requirements, 
different attainment dates, etc. As a result, CAA section 176(c)(5) 
requires conformity requirements to be met in both 1997 and 2006 
PM2.5 nonattainment and maintenance areas, as applicable.
    Some areas designated nonattainment for the 2006 PM2.5 
NAAQS have never been subject to PM2.5 conformity 
requirements. Under today's final rule and CAA section 176(c)(5), these 
areas must meet conformity requirements only for the 2006 
PM2.5 NAAQS, and not for the 1997 PM2.5 NAAQS, 
because these areas are not designated nonattainment for the 1997 
PM2.5 NAAQS.
    Other areas designated nonattainment for the 2006 PM2.5 
NAAQS have been designated also, in whole or in part, for the 1997 
PM2.5 NAAQS. (See Section III.A. for the clarification that 
EPA has made in designations for the 1997 PM2.5 NAAQS 
areas.) These areas must continue to meet their existing conformity 
requirements for the 1997 PM2.5 NAAQS as well as those that 
apply for the 2006 PM2.5 NAAQS.
    One commenter was concerned that, given identical boundaries, an 
area could potentially be required to prepare conformity determinations 
for three different PM NAAQS (i.e., the 24-hr PM10 NAAQS, 
1997 PM2.5 NAAQS, and 2006 PM2.5 NAAQS), and 
believed that this could mean three separate analyses would be 
required. This commenter recommended that an area should only have to 
model to the most restrictive NAAQS.
    As described in the May 2009 proposal, nonattainment designations 
for these NAAQS are different designations with separate SIP 
requirements, different attainment dates, etc. As a result, CAA section 
176(c)(5) requires conformity to be met for all of the NAAQS for which 
an area has been designated. However, MPOs subject to more than one PM 
NAAQS will be able to use existing transportation models and data for 
regional emissions analyses, especially where nonattainment area 
boundaries are the same. Some analysis years for the regional emissions 
analyses will be the same, such as the last year of the transportation 
plan. In addition, MPOs in areas designated for more than one PM NAAQS 
will be able to meet consultation and other conformity requirements 
through the existing processes.
    Furthermore, if an area is designated nonattainment for both the 
1997 and 2006 PM2.5 NAAQS and it has no adequate or approved 
PM2.5 budgets, it could use the same interim emissions test 
for both NAAQS (see Section V.; note that the baseline year for these 
two NAAQS are different, see Section IV.) If such an area has budgets 
only for the 1997 PM2.5 NAAQS, conformity determinations for 
the 2006 PM2.5 NAAQS will be based on the same conformity 
test--i.e., the budget test--that is being used for the 1997 
PM2.5 NAAQS (note that the attainment year for each of these 
NAAQS, which is a required analysis year for the budget test, will 
differ). As described in Section VI., MPOs must use any adequate or 
approved SIP budgets for the 1997 PM2.5 NAAQS for conformity 
determinations that are made prior to SIP budgets for the 2006 
PM2.5 NAAQS being found adequate or approved.
    Today's final rule does not impact project-level conformity 
requirements for the 1997 PM2.5 NAAQS. For example, this 
rule does not substantively change the PM2.5 hot-spot 
analysis requirements, and EPA and FHWA's existing qualitative guidance 
for such analyses continues to be available.\20\ For the purposes of 
PM2.5 conformity, a hot-spot analysis must address the 
PM2.5 NAAQS for which the area has been designated 
nonattainment.\21\ See Section VII. for further information regarding 
project-level conformity requirements for the 2006 PM2.5 
NAAQS.
---------------------------------------------------------------------------

    \20\ ``Transportation Conformity Guidance for Qualitative Hot-
spot Analyses in PM2.5 and PM10 Nonattainment 
and Maintenance Areas,'' EPA420-B-06-902, March 2006.
    \21\ EPA notes that today's final rule does not address project 
requirements for the National Environmental Policy Act or other 
environmental programs.
---------------------------------------------------------------------------

    EPA will work with PM2.5 nonattainment areas as needed 
to ensure that state and local agencies can meet conformity 
requirements for both the applicable 1997 and 2006 PM2.5 
NAAQS in a timely and efficient manner.

E. Precursors That Apply for 2006 PM2.5 Conformity

    The existing transportation conformity rule at 40 CFR 93.102(b) 
describes the pollutants and precursors that must be examined in a 
regional emissions analysis in PM2.5 areas, and these 
provisions apply to 2006 PM2.5 areas as well as 1997 
PM2.5 areas. Direct PM2.5 must be analyzed per 40 
CFR 93.102(b)(1). Before SIP budgets are adequate or approved, 
NOX must also be analyzed, unless both EPA and the state air 
quality agency find that transportation-related emissions of 
NOX are not a significant contributor to the 
PM2.5 nonattainment problem and notify the MPO and DOT (40 
CFR 93.102(b)(iv)).\22\ Before SIP budgets are adequate or approved, 
VOCs, sulfur dioxide, and ammonia do not have to be analyzed unless 
either EPA or the state air quality agency finds that such a precursor 
is a significant contributor, and notifies the MPO and DOT (40 CFR 
93.102(b)(v)). Similarly, before SIP budgets are adequate or approved, 
road dust does not have to be included in the regional emission 
analysis of directly

[[Page 14265]]

emitted PM2.5 unless EPA or the state air agency find that 
re-entrained road dust emissions are a significant contributor, and 
notifies the MPO and DOT (40 CFR 93.102(b)(3)).
---------------------------------------------------------------------------

    \22\ Note that instead of establishing a budget for direct 
PM2.5 or NOX, a SIP could demonstrate that the 
pollutant or precursor is insignificant based on 40 CFR 93.109(k).
---------------------------------------------------------------------------

    Once budgets from a submitted PM2.5 SIP have been found 
adequate or approved, a conformity determination for the 2006 
PM2.5 NAAQS must include any precursors for which budgets 
are established (40 CFR 93.102(b)(iv) and (v)). If road dust is 
included in the direct PM2.5 budget, it must also be 
included in a regional emissions analysis (40 CFR 93.102(b)(3)).
    Please use the interagency consultation process if there are 
questions regarding whether a regional emissions analysis for the 2006 
PM2.5 NAAQS must include specific precursors or road dust.

IV. Baseline Year for Certain 2006 PM2.5 Nonattainment Areas

A. Background

    Conformity determinations for transportation plans, TIPs, and 
projects not from a conforming transportation plan and TIP must include 
a regional emissions analysis that fulfills CAA provisions. The 
conformity rule provides for several different regional emissions 
analysis tests that satisfy CAA requirements in different situations. 
Once a SIP with a motor vehicle emissions budget (``budget'') is 
submitted for an air quality NAAQS and EPA finds the budget adequate 
for conformity purposes or approves it as part of the SIP, conformity 
is demonstrated using the budget test for that pollutant or precursor, 
as described in 40 CFR 93.118.
    Before an adequate or approved SIP budget is available, conformity 
of the transportation plan, TIP, or project not from a conforming 
transportation plan and TIP is demonstrated using the interim emissions 
test(s), as described in 40 CFR 93.119. The interim emissions tests 
include different forms of the ``build/no-build'' test and ``baseline 
year'' test. In general, for the baseline year test, emissions from the 
planned transportation system are compared to emissions that occurred 
in the baseline year. Today's rule updates section 93.119 of the 
conformity rule for the 2006 PM2.5 NAAQS. The baseline year 
for nonattainment areas under the 1997 PM2.5 NAAQS is 2002 
(40 CFR 93.119(e)(2)). Sections V. and VI. of today's final rule go 
into further detail about how the baseline year will be applied in 2006 
PM2.5 areas.

B. Baseline Year for 2006 PM2.5 Areas

1. Description of Final Rule
    In today's final rule, EPA is defining the baseline year as the 
most recent year for which EPA's Air Emissions Reporting Requirements 
(AERR) (40 CFR Part 51) requires submission of on-road mobile source 
emissions inventories,\23\ as of the effective date of EPA's 
nonattainment designations for any PM2.5 NAAQS other than 
the 1997 PM2.5 NAAQS. EPA had proposed this definition under 
``Option 2'' in the proposed rule. AERR requires on-road mobile source 
emission inventories to be submitted every three years, for example, 
2002, 2005, 2008, 2011, etc. See Sec.  93.119(e)(2)(B) for the 
regulatory text.
---------------------------------------------------------------------------

    \23\ 40 CFR 51.30(b).
---------------------------------------------------------------------------

    Today's final rule results in a baseline year of 2008 for the 2006 
PM2.5 areas. The year 2008 is the most recent year as of the 
effective date of the 2006 PM2.5 designations, December 14, 
2009, for which AERR requires submission of on-road mobile source 
emissions inventories. In other words, the designations were effective 
on December 14, 2009, and the most recent year for which an on-road 
mobile source inventory was required as of that date was 2008. 
Therefore, 2008 is the baseline year for 2006 PM2.5 areas.
    This final rule would also govern the baseline year for conformity 
purposes for any areas designated for a PM2.5 NAAQS that EPA 
promulgates in the future. EPA will clarify the relevant baseline year 
under today's regulation for each such future NAAQS for conformity 
implementers in guidance and maintain a list of baseline years that 
result from today's final rule on EPA's Web site.\24\
---------------------------------------------------------------------------

    \24\ See http://www.epa.gov/otaq/stateresources/transconf/
index.htm.
---------------------------------------------------------------------------

    Today's action does not change the 2002 baseline year for areas 
designated nonattainment for the 1997 PM2.5 NAAQS and the 
conformity rule now clarifies that 2002 applies as the baseline year 
only to areas designated nonattainment for the 1997 PM2.5 
NAAQS. The baseline year for 1997 PM2.5 NAAQS areas is found 
in Sec.  93.119(e)(2)(A).
    The existing interagency consultation process (40 CFR 
93.105(c)(1)(i)) must be used to determine the latest assumptions and 
models for generating baseline year motor vehicle emissions to complete 
any baseline year test. The baseline year emissions level that is used 
in conformity must be based on the latest planning assumptions 
available, the latest emissions model, and appropriate methods for 
estimating travel and speeds as required by 40 CFR 93.110, 93.111, and 
93.122 of the current conformity rule. The baseline year test can be 
completed with a submitted or draft baseline year motor vehicle 
emissions SIP inventory, if the SIP reflects the latest information and 
models. If such a SIP baseline is not available, an MPO, in 
consultation with state and local air agencies, could also develop 
baseline year emissions as part of the conformity analysis.
2. Rationale and Response to Comments
    General overview. EPA believes that today's definition for the 
baseline year results in an environmentally protective and legal 
baseline year for conformity under the 2006 PM2.5 NAAQS and 
any future PM2.5 NAAQS revisions, and best accomplishes 
several important goals.
    First, as EPA discussed in the preamble to the proposed rule, EPA 
believes that a more recent year than 2002 (the baseline year for 1997 
PM2.5 areas) is appropriate for meeting CAA conformity 
requirements for 2006 PM2.5 nonattainment areas. EPA also 
believes that using a more recent year is more environmentally 
protective than 2002, and more relevant for the 2006 PM2.5 
NAAQS. Several commenters agreed with these points. Because the AERR 
requires submission of inventories every three years, today's final 
rule results in a baseline year that is recent for any PM2.5 
NAAQS established after 1997. The baseline year will always be either 
the same year as the year in which designations are effective, or one 
or two years prior to the effective date of designations. For example, 
in the case of the 2006 PM2.5 NAAQS, the baseline year, 
2008, is the year before the year in which designations are effective, 
2009.
    EPA had also proposed 2005 as a baseline year as it is also more 
recent than 2002. One commenter preferred a 2005 baseline year because 
the introduction of Tier 2 and improved fuel and engine technologies 
since then would allow transportation plans and TIPs to meet conformity 
more easily. However, because of the implementation of EPA's Tier 2 
Vehicle and Gasoline Program as well as other federal programs, motor 
vehicle emissions in the year 2005 were higher than emissions in the 
year 2008. Thus today's rule, which results in a baseline year of 2008, 
provides more protection for the environment than would a baseline year 
of 2005, in the time before an area has adequate or approved motor 
vehicle emissions budgets from a SIP that addresses PM2.5.
    Second, today's baseline year definition coordinates the conformity

[[Page 14266]]

baseline year with other air quality planning requirements, which 
allows state and local governments to use their resources more 
efficiently. Coordinating the conformity baseline year with the year 
used for SIP planning and an emission inventory year was EPA's 
rationale for using 2002 as the baseline year for conformity tests in 
existing PM2.5 nonattainment areas for the 1997 NAAQS. 
Today's regulatory text results in a conformity baseline year that is 
consistent with emission inventory requirements, and most likely will 
be consistent with the baseline year used for SIP planning as well. 
Several commenters voiced support for coordinating the conformity 
baseline year with these other air quality planning requirements.
    Third, today's final rule provides transportation planners with 
knowledge of the baseline year for any future PM2.5 NAAQS 
upon the effective date of designations for that NAAQS, without having 
to wait either for EPA to amend the transportation conformity rule or 
select a SIP planning baseline year. As a result, MPOs and other 
transportation planners would understand conformity requirements for 
future PM2.5 NAAQS revisions more quickly, which may, in 
turn, also allow more time to prepare and complete necessary conformity 
determinations. Several commenters agreed that not having to wait for a 
rule revision would be a benefit of defining the baseline year as in 
today's rule, rather than choosing a specific year. Some commenters 
preferred defining the baseline year in terms of the year used as the 
baseline year for SIP planning. Today's final rule addresses these 
concerns since it will most likely result in a conformity baseline year 
that is consistent with the SIP baseline year, and in the future will 
give transportation planners the advantage of knowing the baseline year 
at the beginning of the grace period for newly designated areas.
    Last, given that the CAA requires EPA to review the NAAQS for 
possible revision once every five years, today's baseline year 
provision potentially reduces the need for future rule revisions for 
any future PM2.5 NAAQS.
    While today's final rule establishes a baseline year for any 
PM2.5 NAAQS other than the 1997 PM2.5 NAAQS, the 
same rationale would apply for establishing the same type of baseline 
year definition for any future new or revised NAAQS of a 
transportation-related criteria pollutant. Therefore, EPA may amend the 
rule in the future to apply the baseline year language found in today's 
Sec.  93.119(e)(2)(B) more generally. However, EPA did not propose such 
an amendment, and intends to solicit and consider public comment before 
it would adopt any such provision.
    Specific comments. EPA is responding today to several comments 
regarding the baseline year. A couple of commenters indicated that they 
thought proposed Option 2 would create a ``rolling'' baseline year, 
that is, one that would be updated every three years. One commenter did 
not support such a rolling baseline; another did support it as long as 
motor vehicle emissions in an inventory year were less than the prior 
reporting year. However, today's final rule does not establish a 
rolling baseline year for any PM2.5 NAAQS. It establishes a 
single baseline year for each PM2.5 NAAQS that does not 
change over time. For example, for the 2006 PM2.5 NAAQS, the 
definition results in a baseline year of 2008. The year 2008 will 
remain the baseline year for 2006 PM2.5 areas until it's no 
longer needed, i.e., until adequate or approved budgets are available 
in a given area.
    One commenter who supported the option finalized in today's rule 
expressed concern that final emissions data would not be available for 
2008 for some time. However, if a final AERR inventory for 2008 is not 
available in a particular area, there are other options for generating 
the motor vehicle emissions in the baseline year, discussed above under 
``IV.B.1. Description of Final Rule.''
    Another commenter expressed concern that MOVES would not be 
available in time for the year 2008 for the first conformity 
determination for the 2006 PM2.5 NAAQS. At this time, the 
current emissions model, MOBILE6.2, applies for conformity in all areas 
except California, where EMFAC2007 applies. Therefore, if the MOVES 
model is not available to generate a 2008 baseline estimate for use in 
conformity, the MOBILE6.2 model must be used. Once MOVES is available, 
areas can create a new baseline emissions estimate for use in 
conformity using MOVES along with other interim analysis years. EPA 
will provide a policy guidance document for using MOVES in conformity 
determinations that will include more details about when MOVES must be 
used. When available, this guidance will be found on EPA's Web site at: 
http://www.epa.gov/otaq/stateresources/transconf/policy.htm#models. For 
more information on MOVES, please see EPA's Web site at: http://
www.epa.gov/otaq/models/moves/index.htm.
    One commenter thought that the baseline year should be determined 
through interagency consultation. This was not a proposed option. 
However, EPA believes that details for the baseline year test must be 
determined through rulemaking, as EPA has done for other NAAQS since 
1993. Today's rule better accomplishes the purposes of meeting the 
CAA's requirements, coordinating with SIP and inventory planning, and 
providing certainty to transportation planners. Furthermore, today's 
rule ensures consistency across the nation, whereas allowing each area 
to determine its own baseline year through interagency consultation 
could result in different baseline years in different areas.

V. Regional Conformity Tests in 2006 PM2.5 Nonattainment 
Areas That Do Not Have Adequate or Approved SIP Budgets for the 1997 
PM2.5 NAAQS

    This section of the preamble discusses regional conformity tests 
for nonattainment areas for the 2006 PM2.5 NAAQS that do not 
have adequate or approved PM2.5 SIP budgets for the 1997 
NAAQS. This part of the final rule applies to 2006 PM2.5 
nonattainment areas that were not covered by the 1997 PM2.5 
NAAQS, as well as nonattainment areas for both PM2.5 NAAQS 
that do not have an adequate or approved 1997 PM2.5 SIP 
budget. EPA has addressed conformity tests for these areas under 
section 93.109(j) of the conformity rule. See Section VI. of today's 
final rule for conformity tests in 2006 PM2.5 areas that 
have adequate or approved SIP budgets for the 1997 PM2.5 
NAAQS.
    Note that the rule finalizes new requirements for conformity only 
under the 2006 PM2.5 NAAQS. Today's final rule does not 
address or change the requirements for demonstrating conformity for the 
1997 PM2.5 NAAQS.

A. Conformity After 2006 PM2.5 SIP Budgets Are Adequate or Approved

1. Description of Final Rule
    Once a SIP for the 2006 PM2.5 NAAQS is submitted with a 
budget(s) that EPA has found adequate or approved, the budget test must 
be used in accordance with 40 CFR 93.118 to complete all applicable 
regional emissions analyses for the 2006 PM2.5 NAAQS. This 
requirement is found at Sec.  93.109(j)(2). Conformity is demonstrated 
if the transportation system emissions reflecting the proposed 
transportation plan, TIP, or project not from a conforming 
transportation plan and TIP are less than or equal to the motor vehicle 
emissions budget level defined by the SIP as being consistent with CAA 
requirements.
    The first SIP for the 2006 PM2.5 NAAQS could be a 
control strategy SIP

[[Page 14267]]

required by the CAA (i.e., reasonable further progress SIP or 
attainment demonstration) or a maintenance plan. States could also 
voluntarily choose to submit an ``early progress SIP'' prior to 
required SIP submissions. Early progress SIPs must demonstrate a 
significant level of future emissions reductions from a previous year's 
emissions. For example, an area could submit an early progress SIP for 
the 2006 PM2.5 NAAQS that demonstrates a specific percentage 
of emissions reductions (e.g. 5-10%) in an area's attainment year from 
the baseline year emissions (e.g., 2008). An early progress SIP would 
include emissions inventories for all emissions sources for the entire 
2006 PM2.5 nonattainment area and would meet applicable 
requirements for reasonable further progress SIPs. EPA has discussed 
this option in past conformity rule preambles, e.g. the July 1, 2004 
transportation conformity final rule (69 FR 40028), and many states 
have established early progress SIP budgets for conformity purposes.
    Whatever the case, the interim emissions test(s) would no longer be 
used for direct PM2.5 or a relevant precursor once an 
adequate or approved SIP budget for the 2006 PM2.5 NAAQS is 
established and effective for the pollutant or precursor. States are 
required to develop their future 2006 PM2.5 SIPs in 
consultation with MPOs, state and local transportation agencies, and 
local air quality agencies in an effort to facilitate future conformity 
determinations. EPA Regions will be available to assist states in the 
development of early progress SIPs for the 2006 PM2.5 NAAQS, 
if desired.
2. Rationale and Response to Comments
    EPA believes that this provision meets statutory requirements for 
conformity determinations that occur after SIP budgets are available 
for the 2006 PM2.5 NAAQS. Section 176(c) of the CAA states 
that transportation activities must ``conform to an implementation 
plan[hellip]'' (SIP) and states further that conformity to an 
implementation plan means conformity to the SIP's purpose. Once EPA 
finds a budget for the 2006 PM2.5 NAAQS adequate or approves 
the SIP that includes it, the budget test provides the best means to 
determine whether transportation plans and TIPs meet the statutory 
obligations in CAA sections 176(c)(1)(A) and (B) for that NAAQS. That 
is, the budget test best shows that transportation plans and TIPs 
conform to the SIP's purpose of eliminating or reducing the severity 
and number of violations of the NAAQS and achieving expeditious 
attainment of the NAAQS (176(c)(1)(A)); and best confirms the 
requirement that transportation plans and TIPs not cause or contribute 
to any new violation, worsen an existing violation, or delay timely 
attainment or any interim milestones (176(c)(1)(B)). The budget test 
also best demonstrates that transportation plans and TIPs comply with 
the statutory obligation to be consistent with the emissions estimates 
in SIPs, according to CAA section 176(c)(2)(A). By being consistent 
with the on-road mobile source emissions levels in the SIP, 
transportation planners can ensure that their activities remain 
consistent with state and local air quality goals to protect public 
health. EPA received no comments on this aspect of today's rule.

B. Conformity Before 2006 PM2.5 SIP Budgets Are Adequate or Approved

1. Description of Final Rule
    The 2006 PM2.5 nonattainment areas that do not have 
existing adequate or approved PM2.5 budgets for the 1997 
PM2.5 NAAQS must meet one of the following interim emissions 
tests for conformity determinations conducted before adequate or 
approved 2006 24-hour PM2.5 SIP budgets are established:
     The build-no-greater-than-no-build test (``build/no-build 
test''), or
     The no-greater-than-baseline year emissions test 
(``baseline year test'').
    This aspect of today's final rule is similar to the transportation 
conformity rule at 40 CFR 93.119(e) for nonattainment areas for the 
1997 PM2.5 NAAQS. Today's final rule allows 2006 
PM2.5 nonattainment areas without SIP budgets to choose 
between the two interim emissions tests, rather than require that one 
specific test or both tests be completed. Conformity is demonstrated 
if, for each analysis year, the transportation emissions reflecting the 
proposed transportation 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 the baseline year, 
as described in 40 CFR 93.119. For the discussion of the baseline year 
for the 2006 PM2.5 NAAQS, please refer to Section IV. of 
today's notice.
2. Rationale and Response to Comments
    EPA believes that this provision of today's rule meets statutory 
requirements for conformity determinations that occur before SIP 
budgets are available for the 2006 PM2.5 NAAQS. EPA believes 
it is appropriate to provide flexibility and allow 2006 
PM2.5 areas to meet only one interim emissions test before 
adequate or approved PM2.5 SIP budgets are established.
    Using either the build/no-build test or baseline year test is 
sufficient to meet CAA section 176(c)(1)(B) requirements that 
transportation activities do not cause or contribute to new air quality 
violations, worsen existing violations, or delay timely attainment or 
any interim milestones. The baseline year and the build/no-build tests 
are sufficient for demonstrating conformity when an area does not have 
a SIP budget for a portion of a nonattainment area.
    Based on the CAA, EPA has previously determined that only in ozone 
and CO areas of higher classifications \25\ are transportation plans 
and TIPs required to also satisfy section 176(c)(3)(A)(iii), i.e., that 
the transportation plan and TIP contribute to emissions reductions, 
during the time period before adequate or approved SIP budgets are 
available (58 FR 3782-3783; 62 FR 43784-43785; 69 FR 40018, 40019-
40031). As a result, the current rule requires these ozone and CO areas 
to meet both interim emissions tests, rather than only one test.
---------------------------------------------------------------------------

    \25\ These areas include ozone areas classified as moderate and 
above, CO areas classified as moderate with design value greater 
than 12.7 ppm, and CO areas classified as serious.
---------------------------------------------------------------------------

    However, prior to today's rule, the conformity rule already allowed 
areas designated for the other pollutants, as well as the lower 
classifications of ozone and CO, to conform based on only one interim 
emissions test, rather than having to complete two tests and thereby 
contribute further reductions towards attainment. Today's final rule 
requiring the 2006 PM2.5 areas also to meet only one of the 
interim emissions tests meets the CAA's requirements in section 
176(c)(1)(B) (described above in Section II.A., footnote 1). For more 
information and the full rationale for allowing some areas to conform 
based on only one interim emissions test, see the November 24, 1993 
final rule (58 FR 62197) that addressed interim requirements for 
PM10 and NO2 areas, the July 1, 2004 final rule 
(69 FR 40029) that established interim requirements for 1997 
PM2.5 areas, and the May 15, 2009 proposed rule.
    EPA believes that the no-greater-than-baseline year interim 
emissions test is an appropriate test for meeting section 176(c)(1)(B) 
(refer to footnote 1 in Section II.A.) requirements in 2006 
PM2.5 nonattainment areas. By definition, the no-greater-
than baseline year test ensures that emissions from on-road mobile 
sources are no greater than they were during the baseline year that 
will most likely be used for 2006

[[Page 14268]]

PM2.5 NAAQS SIP planning purposes. If future on-road 
emissions do not increase above their base year levels, applicable 
statutory requirements are met.
    The build/no-build test also allows a 2006 PM2.5 area to 
meet statutory requirements. As described above, the build/no-build 
test requires a regional emissions analysis to demonstrate that the 
emissions from the proposed transportation system in future years would 
be less than the emissions from the built transportation system in 
future years. Since for each analysis year, a new transportation plan, 
TIP, or project (the build scenario) could not result in regional 
emissions that are higher than those that would occur in the absence of 
the proposed transportation activities (the no-build scenario) for the 
system, CAA section 176(c)(1)(B) requirements are met. For these 
reasons, EPA believes that the build/no-build test continues to be an 
appropriate interim test prior to SIP budgets being available.
    Most commenters supported allowing 2006 PM2.5 areas to 
meet only one of the interim emissions tests because it would give 
areas the flexibility to use the test they deem most appropriate, given 
the available data and the unique circumstances of individual areas. 
However, one commenter objected, arguing that the rule doesn't promote 
the CAA or the SIP process because it doesn't require reduction of 
PM2.5 emissions. The commenter also stated that the case EPA 
cited in its proposal, Environmental Defense v. EPA 467 F .3d 1329 (DC 
Cir. 2006), is not pertinent because it did not consider climate change 
factors in any way.
    EPA disagrees. First, it has already been clearly established in 
case law that the conformity provisions of the CAA do not require that 
transportation projects achieve additional emission reductions in 
PM2.5 areas before SIP budgets are available. As discussed 
above, allowing 2006 PM2.5 areas the choice of interim 
emissions tests does meet the CAA's requirements. Today's rule is 
parallel to the current rule's requirements for 1997 PM2.5 
nonattainment areas (69 FR 40028-40031), which were upheld by an 
October 2006 court decision. Environmental Defense v. EPA, 467 F.3d 
1329 (D.C. Cir. 2006).\26\ Contrary to the commenter's view, this court 
case is not rendered irrelevant because it doesn't consider climate 
change factors; conformity applies only to nonattainment and 
maintenance areas for transportation-related criteria pollutants and 
their precursors.
---------------------------------------------------------------------------

    \26\ Petitioners challenged several aspects of the conformity 
regulations. In its decision, the U.S. Court of Appeals for the 
District of Columbia Circuit upheld EPA's regulations at 40 CFR 
93.119(b)(2), (d), and (e) ``because the Act does not require that 
activities involving transportation actually reduce pollutants, but 
merely not frustrate an implementation plan's purpose to reduce 
overall emissions.'' The court also upheld EPA's regulations at 40 
CFR 93.118(b), (d), and (e)(6). The court vacated a narrow provision 
at 40 CFR 93.109(e)(2)(v) which had allowed 8-hour ozone areas to 
avoid using their existing 1-hour budgets under certain 
circumstances. This provision was removed from the transportation 
conformity regulation in the January 24, 2008 final rule (see 73 FR 
4434).
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    The same commenter thought that the 2006 court case does not 
preclude EPA from reasonably determining that more stringent interim 
rules are required to ``conform to a SIP's purpose of reducing overall 
emissions.'' However, EPA believes that the best interpretation of the 
Act is that reflected in today's rule, which allows 2006 
PM2.5 areas the choice between the interim emissions tests. 
This interpretation is also consistent with past rulemakings for 
interim emissions test requirements for other pollutants, as described 
above.
    Finally, one commenter asked EPA to clarify whether an area that is 
currently using one of the interim emissions tests for the 1997 
PM2.5 NAAQS could use the results of that test for the 2006 
PM2.5 NAAQS. When areas are determining conformity for the 
1997 and 2006 PM2.5 NAAQS at the same time, they could apply 
some of the information developed in the 1997 PM2.5 regional 
emissions analysis in creating 2006 PM2.5 regional emissions 
analysis.
    First, note that regardless of whether the area is using the 
baseline year test or build/no-build test, the same analysis years can 
be used for 1997 PM2.5 conformity and 2006 PM2.5 
conformity when the analyses are done at the same time (refer to 40 CFR 
93.119(g) for analysis year requirements).
    In most 1997 PM2.5 areas, conformity applies only for 
the annual NAAQS.\27\ While the results of an interim emissions test 
for the 1997 annual PM2.5 NAAQS cannot be directly applied 
for the 2006 24-hour PM2.5 NAAQS, the option described below 
could save implementers some effort when conformity is being determined 
for both of these NAAQS at the same time. This option applies only when 
using MOBILE6.2 for regional emissions analyses.\28\
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    \27\ There are two areas where conformity for both the 1997 
annual and 24-hour NAAQS applies. See Section III.A. for more 
information.
    \28\ Areas in California should use the interagency consultation 
process to determine appropriate methods. In all other 2006 
PM2.5 areas, EPA expects that MOBILE6.2 will be used for 
the first 2006 PM2.5 conformity determinations.
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    Areas should develop the annual emissions for the 1997 
PM2.5 NAAQS by estimating emissions in two seasons, summer 
and winter; four seasons; or the 12 months of the year.\29\
---------------------------------------------------------------------------

    \29\ This description reflects how analyses are to be done for 
the 1997 PM2.5 NAAQS, which is covered in ``Guidance for 
Creating Annual On-Road Mobile Source Emission Inventories for 
PM2.5 Nonattainment Areas for Use in SIPs and 
Conformity,'' EPA420-B-05-008, August 2005, found on EPA's Web site 
at: http://www.epa.gov/otaq/stateresources/transconf/policy/
420b05008.pdf. In particular, Question 7 on pp. 5-8 of that guidance 
addresses how analyses are to be done for the 1997 PM2.5 
NAAQS.
---------------------------------------------------------------------------

    To apply information from the analysis done for the 1997 
PM2.5 NAAQS to the 2006 PM2.5 analysis, for each 
analysis year, areas should use the emission factors developed in the 
1997 PM2.5 NAAQS regional emissions analysis for 
PM2.5 and NOX in a season or month where 
violations of the 2006 PM2.5 NAAQS occurred, and multiply 
these emission factors by the seasonally-adjusted average daily VMT for 
the area of the analysis year.\30\ If violations occurred in more than 
one season or month, the interagency consultation process should be 
used to choose the season or month that would best ensure that the CAA 
is met, for example by choosing the season with the most frequent or 
most severe violations, or the season with the highest vehicle miles 
traveled, or both.\31\ The choice of season or seasons should be based 
on air quality data from the three years used to make designations 
(i.e., 2006-2008), unless more recent air quality data indicates that a 
different season should be analyzed, as decided through consultation.
---------------------------------------------------------------------------

    \30\ If a 24-hour emissions estimate is available in the 
appropriate season or month because this step has been completed for 
1997 PM2.5 NAAQS conformity and conformity is being 
determined for the 1997 PM2.5 NAAQS and the 2006 
PM2.5 NAAQS at the same time, it does not need to be 
redone but can be applied in the regional emissions analysis for 
2006 PM2.5 conformity.
    \31\ Note that this guidance regarding the choice of season 
applies only when using MOBILE6.2 and not MOVES because MOBILE6.2 
PM2.5 emission factors are not sensitive to changes in 
temperature. EPA will provide guidance on this issue when MOVES is 
released. See EPA's Web site at: http://www.epa.gov/otaq/models/
moves/index.htm and http://www.epa.gov/otaq/stateresources/
transconf/policy.htm for future MOVES guidance.
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    Whatever season is chosen to estimate the build scenario emissions, 
the same season should be used for comparison whether using the 
baseline year test or build/no-build test. For example, emissions for a 
build scenario calculated using winter MOBILE6.2 inputs should be 
compared to emissions in the winter of the baseline year, or emissions 
in winter from the no-build scenario.

[[Page 14269]]

    Note that after the effective date of today's final rule, the 
baseline year for the 2006 PM2.5 NAAQS will be 2008 while 
the baseline year for the 1997 PM2.5 NAAQS remains 2002. See 
Section IV. for additional discussion of the baseline year.
    As stated above, once an area has adequate or approved budgets for 
any PM2.5 NAAQS, it must use the budget test instead of an 
interim emissions test.

C. Implementation of Regional Tests

    The existing conformity rule's general requirements for 
PM2.5 regional emissions analyses apply to 2006 
PM2.5 areas that do not have adequate or approved SIP 
budgets for the 1997 PM2.5 NAAQS. EPA is including this 
discussion of the existing regulation's requirements for clarity, to 
help readers understand how the existing regulation applies to areas 
designated nonattainment for the 2006 PM2.5 NAAQS. The 
discussion below is intended to illustrate how today's final rule is to 
be implemented in practice for 2006 PM2.5 areas without 
adequate or approved 1997 PM2.5 SIP budgets.
1. Decisions Made Through the Interagency Consultation Process
    The existing rule's consultation process must be used to determine 
the test for completing any regional emissions analysis for the 2006 
PM2.5 NAAQS, as required by 40 CFR 93.105(c)(1)(i). The 
existing interagency consultation process must also be used to 
determine the latest assumptions and models for generating motor 
vehicle emissions regardless of the test used. Refer to Section IV. of 
this preamble for details about generating baseline year emissions if 
that interim emissions test is selected for a given conformity 
determination.
    In addition, the consultation process must be used to determine 
which analysis years should be selected for regional emissions 
analyses. Before an adequate or approved 2006 PM2.5 budget 
is available, areas would be able to choose, through interagency 
consultation, either interim emissions test for each conformity 
determination. However, the same test must be used for each analysis 
year for a given 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 may indicate that an area would not 
conform using one test consistently.
2. How a Regional Emissions Analysis Can Be Developed When Using An 
Interim Emissions Test
    Under the ``Rationale and Response to Comments'' above, EPA 
described how an area using an interim emissions test for 1997 
PM2.5 conformity could apply it to 2006 PM2.5 
conformity. This section provides general guidance for creating a 2006 
PM2.5 regional emissions analysis.
    Because the 2006 PM2.5 NAAQS designations were only for 
the 2006 24-hour PM2.5 NAAQS, the regional emissions 
analysis will be based on emissions for a 24-hour time period.
    For either the baseline year test or the build/no-build test, for 
each analysis year, emissions must be estimated for the build scenario 
according to 40 CFR 93.119(i) with a 24-hour emissions inventory. (The 
build scenario is referred to as the ``Action'' scenario at 40 CFR 
93.119(i).)
    This emissions inventory would include direct PM2.5, 
NOX, and any other relevant precursor emissions \32\ that 
result from the build scenario using MOBILE6.2 for a 24-hour period. 
For each analysis year chosen, areas should choose MOBILE6.2 inputs for 
the season of the year where violations of the 2006 PM2.5 
NAAQS occurred.\33\ If violations occurred in more than one season, 
implementers should use the interagency consultation process to choose 
the season (or seasons) that would best ensure that the CAA is met, for 
example by choosing the season with the most frequent or most severe 
violations, or the season with the highest vehicle miles traveled, or 
both.\34\ The choice of season or seasons should be based on air 
quality data from the three years used to make designations (i.e., 
2006-2008), unless more recent air quality data indicates that a 
different season should be analyzed, as decided through consultation.
---------------------------------------------------------------------------

    \32\ Refer to 40 CFR 93.102(b) for which precursors apply. To 
date, before they have adequate or approved budgets from a 
PM2.5 SIP, PM2.5 areas have determined 
conformity for only direct PM2.5 and NOX.
    \33\ In California where EMFAC is used, areas should use the 
interagency consultation process to determine appropriate methods.
    \34\ Note that this guidance regarding the choice of season 
applies only when using MOBILE6.2 and not MOVES because MOBILE6.2 
PM2.5 emission factors are not sensitive to changes in 
temperature. EPA will provide guidance on this issue when MOVES is 
released. See EPA's Web site at: http://www.epa.gov/otaq/models/
moves/index.htm and http://www.epa.gov/otaq/stateresources/
transconf/policy.htm for future MOVES guidance.
---------------------------------------------------------------------------

    For each analysis year, these emission factors from MOBILE6.2 for 
direct PM2.5, NOX, and any other relevant 
precursor for the season chosen should be multiplied by the seasonally-
adjusted average daily VMT in that analysis year to create an estimate 
of transportation emissions in a 24-hour period. For additional 
guidance on creating daily emissions inventories, refer to EPA's 
existing guidance documents.\35\
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    \35\ Specifically, see EPA's ``Technical Guidance on the Use of 
MOBILE6.2 for Emission Inventory Preparation,'' EPA420-R-04-013, 
August 2004, found on EPA's Web site at: http://www.epa. gov/otaq/
models/mobile6/420r04013.pdf and ``Procedures for Emission Inventory 
Preparation--Vol IV: Mobile Sources,'' found at: http://ntl.bts.gov/
DOCS/AQP.html.
---------------------------------------------------------------------------

    Note that whatever season is chosen to estimate the build scenario 
emissions, the same season should be used for comparison whether using 
the baseline year test or build/no-build test. For example, emissions 
for a build scenario calculated using winter MOBILE6.2 inputs should be 
compared to emissions in the winter of the baseline year (see Section 
IV. for a discussion of the baseline year in 2006 PM2.5 
areas), or emissions in winter from the no-build scenario.
    Refer to 40 CFR 93.119 for additional information about conducting 
the build/no-build and baseline year tests.
3. Conformity Test Requirements for All Areas
    Regional emissions analyses under today's final rule are to be 
implemented through existing conformity requirements such as 40 CFR 
93.118, 93.119, and 93.122. For example, the existing conformity rule 
requires that certain years within the transportation plan (or 
alternate timeframe) be examined. Under 40 CFR 93.118(d), the following 
years would be analyzed for the budget test with 2006 PM2.5 
SIP budgets:
     The attainment year for the 2006 PM2.5 NAAQS 
(if it is within the timeframe of the transportation plan and 
conformity determination);
     The last year of the timeframe of the conformity 
determination (40 CFR 93.106(d)); and
     Intermediate years as necessary so that analysis years are 
no more than ten years apart.
    For the interim emissions tests, the existing conformity rule (40 
CFR 93.119(g)) requires the following analysis years:
     A year no more than five years beyond the year in which 
the conformity determination is being made;
     The last year of the timeframe of the conformity 
determination (as described in 40 CFR 93.106(d));
     Intermediate years as necessary so that analysis years are 
no more than 10 years apart.

[[Page 14270]]

See the relevant regulatory sections of the conformity rule and the 
July 1, 2004 final rule preamble for further background on how tests 
have been implemented for other pollutants and NAAQS (69 FR 40020).
4. Cases Involving Multi-Jurisdictional Areas
    In July 2004, EPA issued a guidance document for implementing 
conformity requirements in multi-jurisdictional areas.\36\ Multi-
jurisdictional areas are nonattainment and maintenance areas with 
multiple MPOs, one or more MPOs and a donut area, or multi-state areas. 
EPA believes that this guidance should also apply to 2006 
PM2.5 areas with multiple jurisdictions.
---------------------------------------------------------------------------

    \36\ ``Companion Guidance for the July 1, 2004, Final 
Transportation Conformity Rule: Conformity Implementation in Multi-
Jurisdictional Nonattainment and Maintenance Areas for Existing and 
New Air Quality Standard,'' EPA420-B-04-012, July 2004, found on 
EPA's Web site at http://www.epa.gov/otaq/stateresources/transconf/
policy/420b04012.pdf.
---------------------------------------------------------------------------

    There are two parts of this existing guidance that are most 
relevant for implementing conformity for multi-jurisdictional 2006 
PM2.5 areas that do not have adequate or approved 1997 
PM2.5 SIP budgets. Part 2 of this guidance describes how 
conformity would be implemented in all 2006 PM2.5 areas 
before adequate or approved SIP budgets are available for an applicable 
NAAQS. Part 3 of this guidance is relevant for meeting conformity 
requirements once adequate or approved 2006 PM2.5 SIP 
budgets are available.
    For example, Part 3 of this guidance describes how a state or MPO 
in a multi-state nonattainment area can operate independently from 
other states/MPOs for conformity purposes once adequate or approved SIP 
budgets for a state are established. This same conformity guidance also 
applies for the 2006 PM2.5 NAAQS in these types of areas. 
Part 3 applies to the cases where subarea budgets are established for a 
nonattainment area within one state with multiple MPOs. For further 
information, please refer to EPA's 2004 multi-jurisdictional conformity 
guidance.

VI. Regional Conformity Tests in 2006 PM2.5 Areas That Have 
Adequate or Approved 1997 PM2.5 SIP Budgets

    This section describes the conformity tests required for completing 
regional emissions analyses in areas designated for the 2006 
PM2.5 NAAQS that have adequate or approved SIP budgets for 
the 1997 PM2.5 NAAQS that cover either part or all of the 
2006 PM2.5 area. The conformity tests for these areas are 
found under a new section 93.109(k). See Section V. of this preamble 
for conformity tests in 2006 PM2.5 areas that do not have an 
adequate or approved 1997 PM2.5 SIP budget.

A. Conformity After 2006 PM2.5 SIP Budgets Are Adequate or Approved

1. Description of Final Rule
    Once a SIP for the 2006 PM2.5 NAAQS is submitted with 
budget(s) that EPA has found adequate or approved, the budget test must 
be used in accordance with 40 CFR 93.118 to complete all applicable 
regional emissions analyses for the 2006 PM2.5 NAAQS. 
Conformity is demonstrated if the transportation system emissions 
reflecting the proposed transportation plan, TIP, or project not from a 
conforming transportation plan and TIP were less than or equal to the 
motor vehicle emissions budget level defined by the SIP as being 
consistent with CAA requirements.
    The first submitted SIP for the 2006 PM2.5 NAAQS may be 
an attainment demonstration or a maintenance plan. Nonattainment areas 
for the 2006 PM2.5 NAAQS could also voluntarily choose to 
submit an ``early progress SIP'' to establish budgets for conformity 
purposes prior to required SIPs. See Section V. for further details on 
requirements for early progress SIPs. EPA has discussed this option in 
past conformity rule preamble, e.g. the July 1, 2004 transportation 
conformity final rule (69 FR 40028), and some states have established 
early progress SIP budgets for conformity purposes.
    Whatever the case, interim emissions tests and/or any existing 1997 
PM2.5 SIP budget would no longer be used for conformity in 
2006 PM2.5 areas for direct PM2.5 or a relevant 
precursor once an adequate or approved SIP budget for the 2006 
PM2.5 NAAQS is established for the pollutant or precursor. 
Once a SIP budget for the 2006 PM2.5 NAAQS is adequate or 
approved, the budget test for 2006 PM2.5 conformity would be 
done based on 24-hour emissions (i.e., tons per day). As noted earlier 
in Section III.D., areas that were also designated for the 1997 
PM2.5 NAAQS would continue to meet their existing conformity 
requirements for the 1997 PM2.5 NAAQS, which would include a 
regional emissions analysis based on annual emissions (i.e., tons per 
year). The conformity rule at 40 CFR 93.105 requires consultation on 
the development of SIPs; EPA encourages states to consult with MPOs, 
state and local transportation agencies, and local air quality agencies 
sufficiently early when developing 2006 PM2.5 SIPs to 
facilitate future conformity determinations. Once EPA's nonattainment 
designations are finalized, EPA Regions would be available to assist 
states in developing early progress SIPs for the 2006 PM2.5 
NAAQS, if desired.
2. Rationale and Response to Comments
    EPA's rationale for the use of the budget test once adequate or 
approved SIP budgets addressing the 2006 PM2.5 NAAQS are 
available, and the summary of comments received on this provision, is 
found in Section V.A.2. of this preamble. It is not repeated here.

B. Conformity Before 2006 PM2.5 SIP Budgets Are Adequate or Approved

1. Description of the Final Rule
    This portion of the final rule is for completing conformity under 
the 2006 PM2.5 NAAQS before 2006 PM2.5 SIP 
budgets are established. For areas designated nonattainment for the 
2006 PM2.5 NAAQS where all, or a portion, of the area is 
covered by adequate or approved 1997 PM2.5 SIP budgets, the 
1997 PM2.5 SIP budgets serve as the surrogate for budgets 
for the 2006 PM2.5 NAAQS until the point when 2006 
PM2.5 SIP budgets are adequate or approved. The interagency 
consultation process should be used if there are questions about what 
adequate or approved budgets are established in an area's 1997 
PM2.5 SIP. In addition, in the case where the 1997 budget 
does not cover the entire 2006 PM2.5 area, one of the 
interim emissions tests must also be used, as described below. Section 
IV. of today's rule covers the baseline year to be used for the 
baseline year interim emissions test and Section V. covers interim 
emissions tests in 2006 PM2.5 areas before adequate or 
approved SIP budgets for the 2006 PM2.5 NAAQS are available.
    Many nonattainment areas for the 1997 PM2.5 NAAQS may 
have adequate or approved SIP budgets for the 1997 annual 
PM2.5 NAAQS. For areas that use annual PM2.5 
budgets to meet 2006 PM2.5 requirements, a regional 
emissions analysis would be done based on an analysis of annual, rather 
than 24-hour, emissions (i.e., tons per year).
    The final rule creates a new provision in Sec.  93.109(k) that 
covers the four possible scenarios that could result when areas are 
designated nonattainment for the 2006 PM2.5 NAAQS:
     Scenario 1: the 2006 PM2.5 area nonattainment 
boundary is the same as the 1997 PM2.5 area boundary.

[[Page 14271]]

     Scenario 2: the 2006 PM2.5 area is smaller than 
(and completely within) the 1997 PM2.5 area boundary.
     Scenario 3: the 2006 PM2.5 area is larger than 
(and contains) the 1997 PM2.5 area boundary.
     Scenario 4: the 2006 PM2.5 area boundary 
overlaps with a portion of the 1997 PM2.5 area boundary.
    Most of the 2006 PM2.5 areas that are also designated 
for the 1997 PM2.5 NAAQS are Scenario 1 areas; there are 
areas that belong to Scenarios 2 and 3 as well. EPA is including rules 
for all four scenarios for the sake of completeness.\37\ The following 
paragraphs describe today's rule provisions for each possible scenario 
for 2006 PM2.5 nonattainment areas.
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    \37\ Today's final rule is based on EPA's experience in 
establishing conformity requirements for areas designated for the 
1997 8-hour ozone NAAQS that had SIP budgets for the 1-hour ozone 
NAAQS, found in 40 CFR 93.109(e)(2). The four boundary scenarios are 
the same as the four boundary scenarios EPA described for the 1997 
8-hour ozone areas that had existing 1-hour ozone budgets. EPA's 
2004 guidance entitled, ``Companion Guidance for the July 1, 2004 
Final Transportation Conformity Rule, Conformity Implementation in 
Multi-Jurisdictional Nonattainment and Maintenance Areas for 
Existing and New Air Quality Standards,'' (EPA420-B-04-012), 
contains diagrams of the four scenarios for 8-hour ozone areas. 
Readers may be interested in reviewing these diagrams as they read 
the following description of the regulation. This document can be 
found on EPA's transportation conformity website at: http://
www.epa.gov/otaq/stateresources/transconf/policy/420b04012.pdf.
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    Scenario 1: 2006 PM2.5 areas where the nonattainment boundary is 
exactly the same as the 1997 PM2.5 boundary. In this case, the 2006 and 
1997 PM2.5 nonattainment boundaries cover exactly the same 
geographic area. Such areas must meet the budget test for the 2006 
PM2.5 NAAQS using existing adequate or approved SIP budgets 
for the 1997 PM2.5 NAAQS.
    Scenario 2: 2006 PM2.5 areas where the boundary is smaller than and 
within the 1997 PM2.5 boundary. In this case, the 2006 PM2.5 
nonattainment area is smaller than and completely encompassed by the 
1997 PM2.5 nonattainment boundary. Such areas must meet one 
of the following versions of the budget test:
     The budget test using the subset or portion of existing 
adequate or approved 1997 PM2.5 SIP budgets that applies to 
the 2006 PM2.5 nonattainment area, where such portion(s) can 
be appropriately identified; or
     The budget test using the existing adequate or approved 
1997 PM2.5 SIP budgets for the entire 1997 PM2.5 
nonattainment area. In this case, any additional reductions beyond 
those addressed by control measures in the 1997 PM2.5 SIP 
would be required to come from the 2006 PM2.5 nonattainment 
area as described below.
    Under today's rule, areas could choose either test each time they 
make a conformity determination. For any particular conformity 
determination, however, the same choice would have to be used for each 
analysis year. EPA believes that to do otherwise would be unnecessarily 
complicated and may indicate that one test option used consistently for 
all analysis years would not demonstrate conformity. The consultation 
process must be used to determine whether using a portion of a 1997 
PM2.5 SIP budget is appropriate and feasible, and if so, how 
deriving such a portion would be accomplished. See the preamble of the 
July 1, 2004 final rule (69 FR 40022-40023) for a description of a 
similar provision for the 1997 8-hour ozone NAAQS.
    A conformity determination using the entire 1997 PM2.5 
budget would have to include a comparison between the on-road regional 
emissions produced in the entire 1997 PM2.5 area and the 
existing 1997 PM2.5 SIP budget(s). However, if additional 
reductions are required to meet conformity beyond those produced by 
control measures in the 1997 PM2.5 SIP budgets, those 
reductions must be obtained from within the 2006 PM2.5 
nonattainment area only, since the conformity determination is being 
made for the 2006 PM2.5 NAAQS.
    Scenario 3: 2006 PM2.5 areas where the boundary is larger than the 
1997 PM2.5 boundary. In this case, an entire 1997 PM2.5 
nonattainment or maintenance area would be within a larger 2006 
PM2.5 nonattainment area and the 1997 PM2.5 
budgets would not cover the entire 2006 PM2.5 nonattainment 
area. Such areas are required to meet one of the following:
     The budget test using the 1997 PM2.5 budget(s) 
for the 1997 PM2.5 area, that is, the portion of the 2006 
PM2.5 area that lies within the 1997 PM2.5 area 
boundary, and one of the interim emissions tests for either the 
remaining portion of the 2006 PM2.5 nonattainment area, the 
entire 2006 PM2.5 area, or the entire portion of the 2006 
PM2.5 area within an individual state, if 1997 
PM2.5 budgets are established in each state in a multi-state 
area; or
     The budget test using the existing adequate or approved 
1997 PM2.5 SIP budgets for the entire 2006 PM2.5 
nonattainment area.\38\
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    \38\ While the existing regulation for 8-hour ozone areas does 
not explicitly contain this option, it was addressed in the preamble 
to the final rule addressing 8-hour ozone areas (July 1, 2004, 69 FR 
40027).

The budget test must be completed according to the requirements in 40 
CFR 93.118, and the interim emissions test must follow the requirements 
of 40 CFR 93.119.
    Once an area selects a particular interim emissions test and the 
geographic area it will address, the same test must be used 
consistently for all analysis years. The consultation process must be 
used to determine which analysis years should be selected for regional 
emissions analyses where the budget test and interim emissions tests 
are used. It may be possible to choose analysis years that satisfy both 
the budget and interim emissions test requirements for areas using both 
tests prior to adequate or approved 2006 PM2.5 SIP budgets 
being established. Further information regarding the implementation of 
these requirements is illustrated later in this section.
    Scenario 4: 2006 PM2.5 areas where the boundary partially overlaps 
a portion of the 1997 PM2.5 boundary. In this case, the 1997 and 2006 
PM2.5 nonattainment boundaries partially overlap. As in the 
case with Scenario 3 areas, the 1997 PM2.5 budgets would not 
cover the entire 2006 PM2.5 nonattainment area. However, 
unlike Scenario 3 areas, the 2006 area does not contain the entire 1997 
PM2.5 nonattainment or maintenance area. Therefore, 1997 
PM2.5 budgets cannot be the sole test of conformity for the 
2006 PM2.5 NAAQS, since a conformity determination must 
include a regional emissions analysis that includes the entire 2006 
PM2.5 nonattainment area.
    The 2006 PM2.5 areas covered under this scenario must 
use the 1997 PM2.5 budget(s) to meet the budget test for the 
portion of the 1997 PM2.5 area and budgets that overlap with 
the 2006 PM2.5 area boundary, and one of the interim 
emissions tests for either the remaining portion of the 2006 
PM2.5 nonattainment area, the entire 2006 PM2.5 
area, or the entire portion of the 2006 PM2.5 area within an 
individual state, if 1997 PM2.5 budgets are established in 
each state in a multi-state area. Under this final rule, the budget 
test must be completed according to the requirements in 40 CFR 93.118, 
and the interim emissions test must follow the requirements of 40 CFR 
93.119.
    Similar to Scenario 3 areas, once an area selects a particular 
interim emissions test and the geographic area it will address, the 
same test must be used consistently for all analysis years. Further 
information regarding the implementation of these requirements is found 
in the discussion above for Scenario 3, and illustrated later in this 
section.

[[Page 14272]]

2. Rationale and Response to Comments
    General. EPA believes that using the existing 1997 PM2.5 
budgets as a surrogate for the 2006 PM2.5 NAAQS is required 
by the CAA. In Environmental Defense v. EPA, 467 F.3d 1329 (D.C. Cir. 
2006), the Court of Appeals for the District of Columbia Circuit held 
that where a motor vehicle emissions budget developed for the revoked 
1-hour ozone NAAQS existed in an approved SIP, that budget must be used 
to demonstrate conformity to the 8-hour ozone NAAQS until the SIP is 
revised to include budgets for the new NAAQS. EPA reflected the court's 
decision for ozone conformity tests in its January 24, 2008 final rule 
(73 FR 4434).
    While the Environmental Defense case concerned ozone, EPA believes 
the court's holding is relevant for other pollutants for which 
conformity must be demonstrated. Consequently, EPA believes that 2006 
PM2.5 areas that have 1997 PM2.5 budgets must use 
them for 2006 PM2.5 conformity before 2006 PM2.5 
SIP budgets are established.
    The use of the 1997 PM2.5 budgets as a surrogate for the 
2006 PM2.5 NAAQS also would ensure that CAA requirements are 
met. Section 176(c) of the CAA requires that transportation activities 
may not cause or contribute to new violations, worsen existing 
violations, or delay timely attainment or any interim milestones. In 
these areas, the budgets for the 1997 annual PM2.5 NAAQS 
have been the measure of PM2.5 conformity thus far, and have 
been consistent with these areas' PM2.5 air quality progress 
to date. Therefore, using budgets that address the 1997 annual 
PM2.5 NAAQS where no other PM2.5 budgets are 
available ensures that the requirements of CAA 176(c) are met. Once 
2006 PM2.5 budgets are found adequate or approved, the 
budget test for that NAAQS provides the best means to determine whether 
transportation plans, TIPs, or projects meet CAA requirements.
    The budget test is also a better environmental measure than the 
interim emissions tests when SIP budgets for a pollutant or precursor 
are available. As EPA reiterated in its July 1, 2004 final rule (69 FR 
40026), when motor vehicle emissions budgets have been established by 
SIPs, they provide a more relevant basis for conformity determinations 
than the interim emissions tests. EPA believes this is true even though 
in most cases the budgets established for the 1997 PM2.5 
NAAQS would address an annual rather than a 24-hour NAAQS. A 1997 
PM2.5 budget represents the state's best estimate of the 
level of permissible PM2.5 emissions from the on-road 
transportation sector for a particular area. Such a budget is created 
based on local information for that particular area--its population, 
its estimated vehicle miles traveled and other travel data, its transit 
availability, its particular vehicle fleet, its local controls, and so 
forth. Hence EPA believes using budgets, designed for specific areas 
and based on information from those specific areas, is preferable to 
using either of the more generic interim emissions tests. The baseline 
year and the build/no-build tests are sufficient for demonstrating 
conformity when an area does not have a budget for a portion of a 
nonattainment area. However, these interim emissions tests usually do 
not ensure that transportation emissions promote progress for the NAAQS 
to the same extent that the use of motor vehicle emissions budgets do.
    In addition, using the 1997 PM2.5 budgets for 2006 
PM2.5 conformity purposes may also streamline the conformity 
process for areas designated nonattainment for both the 1997 and 2006 
PM2.5 NAAQS. These areas would already be using 1997 
PM2.5 budgets for conformity of that NAAQS. In areas where 
the 1997 and 2006 PM2.5 nonattainment boundaries are the 
same (Scenario 1), today's final rule requires these areas to meet only 
one type of test--the budget test--to demonstrate conformity for both 
the 1997 and 2006 PM2.5 NAAQS, although the attainment year, 
which is a required analysis year, will be different for these two 
NAAQS.
    For multi-state 2006 PM2.5 nonattainment areas, today's 
final rule preserves states' ability to determine conformity 
independently from one another, if a state has already established 
budgets for its own state (and/or MPO(s)) for the 1997 PM2.5 
NAAQS. Further explanation and examples are given below in Section 
VI.C.
    While today's final rule concerns the 2006 PM2.5 NAAQS, 
this same rationale regarding conformity tests would apply for future 
new or revised NAAQS of any transportation-related criteria pollutant. 
Therefore, EPA may amend the rule in the future to apply the conformity 
test language found in today's Sec.  93.109(j) and (k) more generally. 
EPA is not doing so in today's final rule as such a provision was not 
proposed, and EPA intends to solicit and consider public comments on 
applying this language to future new or revised NAAQS before adopting 
any such provision.
    Scenario 1 and 2 areas. Today's final rule for conformity in 2006 
PM2.5 areas before budgets that address that NAAQS are 
available is largely consistent with the process that EPA finalized for 
8-hour ozone areas designated under the 1997 ozone NAAQS where 1-hour 
ozone budgets exist (69 FR 40021-40028). Requirements for Scenario 1 
and 2 areas are identical to the final rule for these 8-hour ozone 
areas. Scenario 2 2006 PM2.5 areas also have the choice of 
adjusting the existing 1997 PM2.5 budgets for the new 
geographical area. As we indicated in the November 5, 2003 proposed 
rule for the 8-hour ozone areas (68 FR 62702), using the relevant 
portion of existing budgets for purposes of conducting conformity 
determinations for a different NAAQS of the same pollutant is 
appropriate since the budgets for the 1997 PM2.5 NAAQS would 
only be used as a surrogate for the 2006 PM2.5 NAAQS. These 
1997 PM2.5 budgets still have to be met in the 1997 
PM2.5 areas.
    Scenario 3 and 4 areas. Some Scenario 3 areas and all Scenario 4 
areas must also meet one of the interim emissions tests, for either the 
portion of the 2006 PM2.5 area not covered by the 1997 
PM2.5 SIP budgets, the entire PM2.5 area, or the 
entire portion of the 2006 PM2.5 area within an individual 
state. As explained in the November 2003 proposed rule for 8-hour ozone 
areas (68 FR 62702), in these cases budgets cannot be the sole test of 
conformity because a conformity determination must include a regional 
emissions analysis that covers the entire nonattainment area.
    However, some Scenario 3 areas may be able to demonstrate 
conformity without an interim emissions test. Scenario 3 
PM2.5 areas have an option that similar 8-hour ozone areas 
also have: The entire larger, newly designated area could meet budgets 
established for the smaller, existing area. In the July 1, 2004 final 
rule, EPA clarified that 8-hour ozone areas have this option. In that 
final rule, EPA noted that while this option was not explicitly 
addressed by the regulatory text, it is consistent with the 
requirements and is available to interested 8-hour ozone areas (69 FR 
40027).
    Finally, EPA believes that statutory requirements are met under the 
proposal to use either interim emissions test when no adequate or 
approved PM2.5 SIP budgets are available. See further 
rationale regarding this flexibility in today's final rule in Section 
V.
    EPA did not receive any specific comments on this portion of the 
rulemaking, but one commenter supported the use of EPA's 2004 multi-
jurisdictional guidance for 2006 PM2.5 areas. This guidance, 
discussed further

[[Page 14273]]

below in C.2. of this section, reflects the requirements finalized 
today.

C. General Implementation of Regional Tests

    Today's final rule applies the existing conformity rule's general 
requirements for PM2.5 regional emissions analyses to all 
2006 PM2.5 areas. As described in Section V.C., EPA is 
including this discussion of the existing regulation's requirements for 
clarity, to help readers understand how the existing regulation would 
apply to areas designated nonattainment for the 2006 PM2.5 
NAAQS.
    The discussion below is intended to illustrate how today's rule 
will be implemented in practice for 2006 PM2.5 areas with 
adequate or approved 1997 PM2.5 SIP budgets.
1. Conformity Test Requirements for Most Areas
    Regional emissions analyses under today's final rule must be 
implemented through existing conformity requirements such as 40 CFR 
93.118, 93.119, and 93.122. For example, the conformity rule requires 
that only certain years within the transportation plan (or alternate 
timeframe) be examined.
    The consultation process must be used to determine which analysis 
years should be selected for regional emissions analyses for the budget 
test. The conformity rule at 40 CFR 93.118(d)(2) requires the following 
analysis years for this test:
     The attainment year for the 2006 PM2.5 NAAQS 
(if it is within the timeframe of the transportation plan and 
conformity determination);
     The last year of the timeframe of the conformity 
determination (40 CFR 93.106(d)); and
     Intermediate years as necessary so that analysis years are 
no more than ten years apart.

    Areas covered by Sec.  93.109(k) of today's final rule will also be 
determining conformity for the 1997 PM2.5 NAAQS, using 
adequate or approved budgets established for that NAAQS, although there 
will be some differences in analysis years required for the 2006 and 
1997 PM2.5 NAAQS (e.g., the attainment year, which is a 
required analysis year, will be different for these two NAAQS).
    See the relevant regulatory sections of the conformity rule and the 
July 1, 2004 final rule preamble for further background on how tests 
have been implemented for other pollutants and standards (69 FR 40020).
2. Cases Involving Multi-Jurisdictional Areas
    As described earlier, EPA issued a guidance document in 2004 for 
implementing conformity requirements in multi-jurisdictional areas. 
There are two parts of this existing guidance that are relevant for 
implementing conformity for these areas. Part 3 of the existing 
guidance describes how conformity would be implemented in all 2006 
PM2.5 areas once adequate or approved SIP budgets for the 
2006 PM2.5 NAAQS are established. Part 4 of this guidance is 
relevant for meeting conformity requirements when only 1997 
PM2.5 budgets are available.\39\
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    \39\ This section of the guidance covers how 8-hour ozone areas 
that have 1-hour ozone budgets would proceed with developing their 
regional emissions analyses and making conformity determinations, 
which is analogous to any 2006 PM2.5 areas that have 1997 
budgets in the interim.
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    This guidance is also applicable for conformity purposes in multi-
state and multi-MPO areas. For example, in multi-state 2006 
PM2.5 nonattainment areas where each state has its own 1997 
PM2.5 SIP budgets, the states could determine conformity for 
the 2006 NAAQS (as well as the 1997 PM2.5 NAAQS) 
independently of each other. In addition, MPOs in areas that have 
subarea budgets for the 1997 PM2.5 NAAQS could use these 
subarea budgets for conformity to the 2006 PM2.5 NAAQS.
    For further information, please refer to Section V.C. and EPA's 
2004 multi-jurisdictional conformity guidance.

VII. Other Conformity Requirements for 2006 PM2.5 Areas

    The conformity regulations already provide the remaining 
requirements that are necessary for conformity under the 2006 
PM2.5 NAAQS. Any existing conformity requirements that are 
listed for ``PM2.5'' areas that have not been revised by 
today's final rule apply to 2006 PM2.5 nonattainment or 
maintenance areas as well. These provisions have already been 
promulgated, based on past rulemakings and rationale, and are unchanged 
by today's rule. For example, a hot-spot analysis is required for 
certain projects in any PM2.5 nonattainment and maintenance 
areas before such projects can be found to conform. These requirements 
are found in Sec. Sec.  93.116(a) and Sec.  93.123(b) of the conformity 
rule, although please note that EPA for other reasons has clarified 
amendments to section 93.116(a) in today's final rule; see Section IX. 
The hot-spot analysis requirements that were promulgated for 
``PM2.5'' areas in the conformity rule did not need to be 
amended to apply to 2006 PM2.5 areas, because they already 
apply for this NAAQS.
    A hot-spot analysis in an area designated for both the 1997 and 
2006 PM2.5 NAAQS would have to demonstrate that the project 
meets the conformity rule's hot-spot requirements for all of the 
PM2.5 NAAQS for which the area is designated nonattainment:
     If an area is designated nonattainment for only the 2006 
PM2.5 NAAQS, the analysis would have to consider only this 
NAAQS;
     If an area is designated nonattainment for the 1997 annual 
NAAQS and the 2006 24-hour NAAQS, the analysis would have to consider 
both NAAQS;
     If an area is designated nonattainment for both the 1997 
annual and 1997 24-hour NAAQS, as well as the 2006 24-hour NAAQS, the 
analysis would have to consider all of these NAAQS.
    Please refer to the March 10, 2006 final rule for additional 
information regarding hot-spot analyses (47 FR 12468) and EPA and 
FHWA's current guidance for implementing this requirement 
(Transportation Conformity Guidance for Qualitative Hot-spot Analyses 
in PM2.5 and PM10 Nonattainment and Maintenance 
Areas, March 2006, EPA420-B-06-902). EPA will also be releasing PM 
quantitative hot-spot modeling guidance in the near future. Please 
check EPA's Web site at: http://www.epa.gov/otaq/stateresources/
transconf/policy.htm.
    Section 93.117 of the conformity rule, which requires project-level 
conformity determinations to comply with any PM2.5 control 
measures in an approved SIP, also applies for conformity under the 2006 
PM2.5 NAAQS. Again, EPA promulgated this requirement in 
general for nonattainment and maintenance areas under the 
PM2.5 NAAQS. See EPA's July 2004 final rule for further 
information on this requirement (69 FR 40036-40037).
    EPA will work with PM2.5 nonattainment areas as needed 
to ensure that state and local agencies can meet existing and new 
conformity requirements for the 2006 PM2.5 NAAQS in a timely 
and efficient manner.

VIII. Transportation Conformity in PM10 Nonattainment and 
Maintenance Areas and the Revocation of the Annual PM10 
NAAQS

A. Background

    On October 17, 2006, EPA issued a final rule establishing changes 
to the PM2.5 and PM10 NAAQS (71 FR 61144). The 
October 2006 final rule retained the

[[Page 14274]]

24-hour PM10 NAAQS of 150 [mu]g/m\3\, and revoked the annual 
PM10 NAAQS of 50 [mu]g/m\3\. EPA made a commitment in the 
October 2006 final rule to provide information regarding how 
transportation conformity will be implemented under the revised 
PM10 NAAQS (71 FR 61215). To satisfy this commitment, EPA 
described which conformity tests would apply in PM10 
nonattainment and maintenance areas (``PM10 areas'') in a 
guidance document.\40\ Today's final rule updates the conformity rule 
in response to this commitment.
---------------------------------------------------------------------------

    \40\ Transportation Conformity in PM10 Nonattainment 
and Maintenance Areas and the Revocation of the Annual 
PM10 Standard, September 25, 2008, found on EPA's Web 
site at: http://www.epa.gov/otaq./stateresources/transconf/
policy.htm.
---------------------------------------------------------------------------

    CAA section 176(c)(5) requires conformity only in areas that are 
designated nonattainment or maintenance for a given pollutant and 
NAAQS. Therefore, transportation conformity has continued to apply to 
all PM10 nonattainment and maintenance areas because 
transportation conformity applies based on an area's status as a 
nonattainment or maintenance area, and PM10 designations 
were not affected by the October 2006 final rule. As stated in the 
October 2006 final rule, ``both transportation and general conformity 
will continue to apply to all PM10 nonattainment and 
maintenance areas since no designations are changing'' (71 FR 61215).
    As of the effective date of the October 2006 rule, conformity 
determinations in PM10 areas have been required only for the 
24-hour PM10 NAAQS. The October 2006 final rule stated, 
``However, because EPA is revoking the annual PM10 NAAQS in 
this final rule, after the effective date of this rule conformity 
determinations in PM10 areas will only be required for the 
24-hour PM10 NAAQS; conformity to the annual PM10 
NAAQS will no longer be required'' (71 FR 61215). Please refer to the 
October 17, 2006 final rule for additional information (71 FR 61144).

B. Description of the Final Rule

    EPA has added two new definitions to 40 CFR 93.101 of the 
conformity rule to distinguish between the 24-hour PM10 
NAAQS and the annual PM10 NAAQS. EPA has also updated 40 CFR 
93.109(g) so that:
     PM10 areas that have adequate or approved SIP 
budgets for both the 24-hour and annual PM10 NAAQS are 
required to use only the budgets established for the 24-hour 
PM10 NAAQS. Conformity to the annual PM10 budgets 
in such a case is no longer required.
     PM10 areas that have adequate or approved SIP 
budgets for only the annual PM10 NAAQS are required to use 
them for PM10 conformity determinations until 
PM10 SIP budgets for the 24-hour PM10 NAAQS are 
found adequate or approved. For areas that use annual PM10 
budgets, a regional emissions analysis must be done based on an 
analysis of annual, rather than 24-hour, emissions.
    No other conformity requirements for PM10 nonattainment 
and maintenance areas have been changed by the final rule. For example, 
the requirement for project-level conformity determinations in 
PM10 areas continues to apply, including hot-spot analyses 
in some cases (see Sec. Sec.  93.116(a) and 93.123(b)). Although 
project-level conformity requirements and any required hot-spot 
analyses apply only with respect to the 24-hour PM10 NAAQS, 
this requires no revisions to the conformity rule to implement.
    Where an area has adequate or approved PM10 budgets for 
both the annual and 24-hour PM10 NAAQS, it is not necessary 
to remove the annual PM10 NAAQS budgets from the SIP. Such 
annual budgets do not apply for conformity purposes if an area has 
budgets for the 24-hour PM10 NAAQS. However, states can 
choose to revise such SIPs to remove any annual PM10 
budgets, since this NAAQS has been revoked and remaining 24-hour 
PM10 budgets ensure that anti-backsliding SIP requirements 
are met.

C. Rationale and Response to Comments

    Today's update to the rule for PM10 conformity tests 
results from the revocation of the annual PM10 NAAQS. In 
areas where annual PM10 budgets are the only PM10 
budgets that are adequate or approved, EPA believes it is necessary to 
use such budgets to demonstrate conformity for the 24-hour 
PM10 NAAQS to meet CAA requirements. As discussed above in 
Section VI.B.2., a 2006 decision by the Court of Appeals for the DC 
Circuit clarified this point. In this decision, the court stated, ``A 
current SIP, even one tied to outdated NAAQS, remains in force until 
replaced by another but later-approved SIP. The CAA provides that the 
current SIPs are legally sufficient until they are replaced by new 
SIPs.'' (Environmental Defense v. EPA, 467 F.3d 1329, 1335 (DC Cir. 
2006)). Refer to Section VI.B.2. for further information about the 
decision. EPA believes that today's final rule is consistent with this 
decision.
    Consequently, EPA believes that annual PM10 budgets must 
be used to demonstrate conformity for the 24-hour PM10 NAAQS 
when adequate or approved 24-hour PM10 budgets are not yet 
established. In areas with PM10 budgets that address only 
the annual PM10 NAAQS, these budgets have been the measure 
of PM10 conformity thus far, and have been consistent with 
these areas' PM10 air quality progress to date. Therefore, 
using annual PM10 budgets where no other PM10 SIP 
budgets are available ensures that air quality progress to date is 
maintained, air quality will not be worsened and attainment and any 
interim milestones for the 24-hour PM10 NAAQS will not be 
delayed because of emissions increases. Once 24-hour PM10 
budgets are found adequate or approved, the budget test using only the 
budgets for the 24-hour PM10 NAAQS provides the best means 
to determine whether transportation plans, TIPs, or projects meet CAA 
conformity requirements.
    Most PM10 areas already have adequate or approved 
budgets for only the 24-hour PM10 NAAQS. However, there are 
a limited number of PM10 areas that have SIP budgets only 
for the annual PM10 NAAQS. EPA believes that the statute as 
interpreted by the court requires such areas to continue to use these 
adequate or approved annual PM10 SIP budgets, rather than 
use one of the interim emissions tests in 40 CFR 93.119(d) which could 
be less environmentally protective tests than SIP budgets.
    While EPA addressed how the revocation affected PM10 
transportation conformity requirements in its September 2008 guidance, 
updating the regulation clarifies the requirements and simplifies 
implementation. This final rule also saves resources in some areas with 
adequate or approved SIP budgets for both the 24-hour and annual 
PM10 NAAQS because these areas are no longer required to use 
budgets for the annual PM10 NAAQS. As mentioned above, 
today's minor revision to the conformity rule is consistent with what 
is already required in the field for PM10 nonattainment and 
maintenance areas.
    EPA received one comment supporting this rule change and no 
comments opposing it.

IX. Response to the December 2007 Hot-Spot Court Decision

A. Background

    EPA promulgated a final rule on March 10, 2006 (71 FR 12468) that 
revised the previous PM10 conformity hot-spot analysis 
requirements and applied these revised requirements to

[[Page 14275]]

PM2.5.\41\ A hot-spot analysis is defined in 40 CFR 93.101 
as an estimation of likely future localized pollutant concentrations 
and a comparison of those concentrations to relevant NAAQS. A hot-spot 
analysis assesses the air quality impacts of an individual 
transportation project on a scale smaller than a regional emissions 
analysis for an entire nonattainment or maintenance area.
---------------------------------------------------------------------------

    \41\ The March 10, 2006 rule constituted final action on EPA's 
original proposal from November 5, 2003 (68 FR 62690, 62712) and a 
supplemental proposal from December 13, 2004 (69 FR 72140, 72144-45, 
and 72149-50).
---------------------------------------------------------------------------

    Prior to today, section 93.116(a) of the conformity rule read: ``* 
* * The FHWA/FTA project must not cause or contribute to any new 
localized CO, PM10, and/or PM2.5 violations or 
increase the frequency or severity of any existing CO, PM10, 
and/or PM2.5 violations * * *.'' These requirements continue 
to apply in today's rule, and are satisfied for applicable projects 
\42\ ``if it is demonstrated that during the time frame of the 
transportation plan 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.'' Sections 93.105(c)(1)(i) and 93.123 contain 
the consultation and methodology requirements for conducting hot-spot 
analyses.
---------------------------------------------------------------------------

    \42\ Section 93.123(b) contains the types of projects for which 
a hot-spot analysis applies in PM2.5 and PM10 
areas. For additional discussion, please refer to ``V. Projects of 
Air Quality Concern and General Requirements for PM2.5 
and PM10 Hot-Spot Analyses'' in the preamble of the March 
10, 2006 final rule at 71 FR 12490-12498.
---------------------------------------------------------------------------

    A hot-spot analysis, when required, is only one part of a project-
level conformity determination. In order to meet all CAA requirements, 
an individual project must also be included in a conforming 
transportation plan and TIP (and regional emissions analysis for the 
entire nonattainment or maintenance area) and meet any other applicable 
requirements.
    Environmental petitioners challenged the March 2006 final rule, and 
raised several issues related to it. First, petitioners alleged that 
the final rule did not ensure that transportation projects complied 
with CAA section 176(c)(1)(A) and (c)(1)(B)(iii). Second, petitioners 
alleged that EPA had previously approved its MOBILE6.2 on-road mobile 
source emissions model for use in quantitative PM2.5 and 
PM10 hot-spot analyses, and withdrew such approval in the 
March 2006 final rule without providing adequate notice and opportunity 
for public comment.\43\
---------------------------------------------------------------------------

    \43\ EPA and petitioners settled a third issue that was not 
raised to the court. The settlement was finalized on June 22, 2007 
(72 FR 34460), and described a stakeholder process that EPA will use 
to develop its future PM2.5 and PM10 
quantitative hot-spot modeling guidance.
---------------------------------------------------------------------------

    On December 11, 2007, the D.C. Circuit Court of Appeals issued its 
decision, and upheld EPA's March 2006 final rule and remanded one issue 
for clarification. Environmental Defense v. EPA, 509 F.3d. 553 (D.C. 
Cir. 2007). The court agreed with EPA's position that CAA section 
176(c)(1)(A) does not require that an individual transportation project 
reduce emissions, but only that such a project not worsen air quality 
compared to what would have otherwise occurred if the project was not 
implemented. The court held that, assuming section 176(c)(1)(A) applies 
in the local area surrounding an individual project, EPA's position 
that this provision is met if a transportation project conforms to the 
emissions estimates and control requirements of the SIP was a 
reasonable one. The court also rejected petitioners' arguments 
regarding MOBILE6.2 and found that EPA had in fact provided adequate 
notice and comment on its decision not to require quantitative PM hot-
spot analyses using MOBILE6.2 due to the model's technical limitations 
at the project-level (71 FR 12498-12502).
    However, the court remanded one issue to EPA for further 
explanation of the Agency's interpretation of CAA section 
176(c)(1)(B)(iii). The court instructed EPA on remand to interpret how 
this provision of the Act is met within the local area affected by an 
individual project, or explain why this statutory provision does not 
apply within such an area. Today's final rule responds to this part of 
the court's decision.

B. Description of the Final Rule

    EPA has made two changes to section 93.116(a) of the conformity 
rule to address the court's remand. First, EPA is explicitly stating in 
this provision that federally funded or approved highway and transit 
projects in PM2.5 and PM10 nonattainment and 
maintenance areas must meet the requirements of CAA section 
176(c)(1)(B)(iii) within the local area affected by the project. That 
is, Sec.  93.116(a) now expressly says that project must not delay 
timely attainment or any interim milestones. EPA has also explicitly 
stated in Sec.  93.116 the requirement that projects must be included 
in a regional emissions analysis under 40 CFR 93.118 or 93.119. 
Consistent with the court's decision, as explained below, EPA is not 
requiring an individual project to reduce emissions in the local 
project area.
    These revisions are intended to clarify and make more explicit 
EPA's longstanding interpretation of the CAA as it applies to hot-spot 
analyses, and do not reflect any substantive changes to existing 
requirements for project-level conformity determinations. Under today's 
final rule, project-level conformity determinations, including any hot-
spot analyses, will continue to be performed in the same manner as 
current practice. Projects will continue to be required to be a part of 
a regional emissions analysis that supports a conforming transportation 
plan and TIP. Hot-spot analyses will need to demonstrate that during 
the time frame of the transportation plan no new local violations would 
be created and the severity or number of existing violations would not 
be increased as a result of a new project. By making these 
demonstrations, it can be assured that the project would not delay 
timely attainment or any required interim reductions or milestones, as 
described further below. In addition, project sponsors must continue to 
document the hot-spot analysis as part of the project-level conformity 
determination, and the public continues to be able to comment on any 
aspects of the conformity determination through existing public 
involvement requirements.
    EPA notes that today's final rule also addresses new projects in CO 
nonattainment and maintenance areas, since the hot-spot analysis 
requirements in section 93.116(a) also apply to such areas. Although 
the March 2006 final rule and the December 2007 court case did not 
involve CO hot-spot requirements, EPA believes it is appropriate to 
clarify that CAA section 176(c)(1)(B)(iii) must also be met for 
projects in CO nonattainment and maintenance areas.

C. Rationale and Response to Comments

1. General
    Project-level conformity determinations must demonstrate that all 
of the requirements in CAA section 176(c)(1)(B) are met. Section 
176(c)(1)(B) defines conformity to a SIP to mean ``that such activities 
will not (i) cause or contribute to any new violation of any NAAQS in 
any area; (ii) increase the frequency or severity of any existing 
violation of any NAAQS in any area; or (iii) delay timely attainment of 
any NAAQS or any required interim emission reductions or other 
milestones in any area.''

[[Page 14276]]

    In Environmental Defense, the court held that EPA did not 
adequately explain how it interpreted the language of CAA section 
176(c)(1)(B)(iii) in conjunction with related language in sections 
176(c)(1)(B)(i) and (ii). The court stated that, if ``any area'' in the 
first two provisions refers to a ``local area,'' then EPA must either 
interpret the term ``any area'' in section 176(c)(1)(B)(iii) to also 
mean ``local area,'' or explain why a different interpretation is 
reasonable. 509 F.3d at 560-61. EPA believes that ``any area'' as used 
in the first two provisions does include local areas, and that the same 
interpretation should apply to the third provision as well; therefore 
all of section 176(c)(1)(B) requirements must be met in the local 
project area.
    EPA believes that its conformity hot-spot regulations, as well as 
other conformity requirements, already require that individual projects 
comply with section 176(c)(1)(B)(iii) in the local project area. EPA 
has always intended the term ``any area'' in all three statutory 
provisions of section 176(c)(1)(B) to include the local area affected 
by the emissions produced by a new project. For example, as EPA stated 
in the March 2006 final hot-spot rule (71 FR 12483), ``a regional 
emissions analysis for an area's entire planned transportation system 
is not sufficient to ensure that individual projects meet the 
requirements of section 176(c)(1)(B) where projects could have a 
localized air quality impact.''
    To implement section 176(c)(1)(B) requirements in PM2.5, 
PM10, and CO nonattainment and maintenance areas (40 CFR 
93.109(b)), EPA's conformity rule has required and continues to require 
project-level conformity determinations to address the regional and 
local emissions impacts from new projects. Section 93.115(a) of the 
conformity rule requires that an individual project must be consistent 
with the emissions projections and control measures in the SIP, either 
by inclusion in a conforming transportation plan and TIP or through a 
separate demonstration (and regional emissions analysis developed under 
40 CFR 93.118 or 93.119). In addition, section 93.116(a) requires that 
some project-level conformity determinations include a hot-spot 
analysis that demonstrates emissions from a single project do not 
negatively impact air quality within the area substantially affected by 
the project.\44\ EPA concludes that through meeting all of these 
requirements, it can be assured that a project does not cause or 
contribute to a new violation, worsen a violation, or delay timely 
attainment or any interim milestones.
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    \44\ Hot-spot analyses must be based on the latest data and 
models under 40 CFR 93.109(b), 93.111, and 93.123, and therefore any 
growth in other emissions sources or the impact of new or existing 
emissions controls (including those in any required SIP) would 
always be considered in a hot-spot analysis prior to approving a 
project.
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    However, in light of the court's request for further explanation, 
today's rule specifically clarifies that the term ``any area'' in CAA 
section 176(c)(1)(B) applies to any portion of a nonattainment or 
maintenance area, including the local area affected by a transportation 
project. Today's final rule thus ensures that transportation planners 
address the requirement that there be no delay in timely attainment or 
any interim milestones in the local project area.
    EPA notes that CAA section 176(c)(1)(B)(iii) does not require that 
transportation activities provide additional emissions reductions in a 
local project area in order to meet the requirement not to delay timely 
attainment or any interim milestones. EPA explained this interpretation 
in the preamble to its March 2006 hot-spot regulations (71 FR 12482), 
and the court upheld this interpretation in Environmental Defense v. 
EPA (509 F.3d 553, 560 (D.C. Cir. 2007). See also Environmental Defense 
v. EPA, 467 F.3d 1329, 1337 (DC Cir. 2006) (``EPA argues, and we agree, 
that conformity to a SIP can be demonstrated by using the build/no-
build test, even if individual transportation plans do not actively 
reduce emissions''). CAA section 176(c)(1)(B)(iii) does not require a 
new project to mitigate new or worsened air quality violations that it 
does not cause. This statutory provision also does not require a new 
project to contribute new interim reductions beyond those that are 
already required in the SIP. Rather, the hot-spot determination must 
instead conclude that the new project, in conjunction with all other 
emissions increases and decreases in the local project area, is 
consistent with the emissions budgets in the SIP and does not produce 
any new or worsen any existing violations.
    The only case where Congress specifically required individual 
projects to provide emission reductions in hot-spot analyses is for 
projects in certain CO nonattainment areas. CAA section 
176(c)(3)(B)(ii) requires individual projects in CO nonattainment areas 
to ``eliminate or reduce the severity and number of violations of the 
carbon monoxide NAAQS in areas substantially affected by the project.'' 
\45\ Since Congress did not establish such a requirement for any 
project in PM2.5 and PM10 areas under section 
176(c)(3)(B)(ii), and for the reasons described in today's final rule, 
EPA does not interpret such a requirement to apply to projects in 
PM2.5 or PM10 areas under section 
176(c)(1)(B)(iii).
---------------------------------------------------------------------------

    \45\ This requirement is in section 93.116(b) of the conformity 
rule.
---------------------------------------------------------------------------

    Some commenters supported EPA's interpretation, while others 
disagreed. The other commenters believed that, despite the court's 
decision, a project should not be allowed to proceed unless it reduces 
emissions sufficient to offset emissions from other sources that 
negatively impact meeting the NAAQS. Commenters thought today's rule 
would allow a project to conform even when there are NAAQS violations 
after the attainment date and that EPA's rule eliminates the 
opportunity to identify and remedy violations.
    The commenters' argument--that section 176(c)(1)(B)(iii) requires 
transportation projects to reduce emissions in the area affected by the 
project--has been raised in earlier transportation conformity 
rulemakings and repeatedly rejected by the D.C. Circuit Court of 
Appeals. In Environmental Defense Fund v. EPA, the court explained that 
``[a]lthough the Act states that SIPs must reduce violations, and 
therefore emissions, it is notably silent on whether transportation 
plans themselves, which are but one part of the SIP, must reduce 
emissions.'' 467 F.3d 1329, 1338 (D.C. Cir. 2006) (emphasis in 
original). The court went on to uphold as reasonable EPA's 
interpretation that individual transportation plans need not reduce 
emissions to comply with the statutory requirement to conform to the 
SIP. Id. In the 2006 EDF decision, the court also referred to its 
earlier decision in Environmental Defense Fund v. EPA, 82 F.3d. 451 
(D.C. Cir. 1996), in which it rejected a challenge to EPA's 1993 
conformity regulations for similar reasons. In the 2006 EDF decision, 
the court noted that it had previously decided a similar issue in the 
1996 EDF opinion, in which it ``agreed with EPA `that plans and 
improvement programs may contribute to emissions reductions by avoiding 
or reducing increases in emissions over the years,' because although 
the statute `require[d] reductions in [several pollutants],' it `d[id] 
not require that the emissions come entirely from mobile sources'[.]'' 
EDF v. EPA, 467 F.3d at 1338. Thus, the 2006 EDF decision was the 
second time the D.C. Circuit rejected the same

[[Page 14277]]

argument commenters raise here. The fact that the 1996 and 2006 D.C. 
Circuit decisions addressed transportation plans and TIPs, rather than 
individual projects, is not relevant because the court's analysis of 
what section 176(c)(1) requires applies equally to transportation 
plans, TIPs, and individual projects, since section 176(c) imposes the 
same requirements for all three, and contains no additional or 
different requirements for individual projects.
    In its 2007 decision in Environmental Defense v. EPA, the court for 
a third time upheld EPA's interpretation that a transportation project 
that does not increase violations of the NAAQS conforms to the SIP's 
purpose of eliminating or reducing the severity and number of NAAQS 
violations and achieving expeditious attainment of the NAAQS, even if 
the project does not itself achieve emissions reductions. 509 F.3d 553, 
560 (DC Cir. 2007). In that decision, the court did remand to EPA for 
further explanation the issue of whether section 176(c)(1)(B)(iii) 
applies to hot-spot analyses, and if it does, how its conditions are to 
be met. Today's final rule responds to that remand. As explained below, 
EPA interprets section 176(c)(1)(B)(iii) as applying to hot-spot 
analyses, and the requirements of the regulations as amended in today's 
action will ensure that transportation projects do not interfere with 
timely attainment of the NAAQS or any interim milestones.
    Section 176(c)(1) prohibits federal agencies from supporting, 
providing financial assistance for, licensing, permitting, or approving 
any activity that does not conform to an approved SIP. This provision 
defines ``conformity to a SIP'' to mean (1) conformity to the SIP's 
purpose of eliminating or reducing the severity and number of NAAQS 
violations and achieving expeditious attainment of the NAAQS, (2) that 
the activity will not cause or contribute to any new violation of the 
NAAQS in any area, (3) that the activity will not increase the 
frequency or severity of any existing NAAQS violation in any area, and 
(4) that the activity will not delay timely attainment of any NAAQS or 
interim milestones. Commenters focus on the fourth requirement above--
that an activity will not delay timely attainment of any NAAQS or any 
interim milestones--to support their argument that EPA's May 2009 
proposal is inconsistent with the CAA because it would allow a new or 
expanded transportation project to conform to the SIP if the project 
does not achieve attainment of the NAAQS. EPA disagrees with the 
commenters' assertion.
    EPA first notes that two of the four elements in the statutory 
definition of ``conformity to an implementation plan'' contain some 
redundancy. Section 176(c)(1)(A) states that ``conformity to an 
implementation plan'' means conformity to the SIP's purpose of 
eliminating or reducing the severity and number of NAAQS violations and 
achieving expeditious attainment of the NAAQS. Section 
176(c)(1)(B)(iii) states that conformity to the SIP means that the 
transportation activity will not delay timely attainment of the NAAQS 
or any interim milestones. Both of these criteria seek to ensure 
attainment of the SIP in a timely manner--by requiring that projects 
not delay timely attainment or any interim milestones in any area and 
thereby ensuring expeditious attainment of the NAAQS. If a project 
conforms to the SIP's purpose of achieving expeditious attainment of 
the NAAQS, it cannot be delaying timely attainment of the NAAQS, since 
``expeditious attainment'' would require attainment at least as early 
as would ``timely attainment.'' ``Expeditious'' means ``characterized 
by speed and efficiency,'' whereas ``timely'' is defined as ``before a 
time limit expires'' or ``done or happening at the appropriate or 
proper time.'' \46\ Thus, EPA is not reading section 176(c)(1)(B)(iii) 
out of the statute, as commenters assert, but is instead reading it in 
conjunction with a closely related provision which also addresses 
projects' relationship to attainment of the NAAQS.
---------------------------------------------------------------------------

    \46\ Definitions from Webster's On-line Dictionary, see http://
www.websters-online-dictionary.org/.
---------------------------------------------------------------------------

    Further, the regulatory requirements for hot-spot analyses meet the 
requirement that a project not delay timely attainment of the NAAQS or 
any interim milestones. See 40 CFR 93.123(c). The hot-spot analysis 
must evaluate air quality concentrations resulting from emissions from 
the project and the future background pollutant concentrations. Such 
concentrations must be examined at receptor locations in the localized 
area substantially affected by the project. Future background 
concentrations at the project location are based on either available 
monitoring data near the project location, or when such information is 
not available, the latest information must be used as determined 
through the interagency consultation process (40 CFR 93.105(c)(1)(i)). 
Based on a review of the available data, the hot-spot analysis must 
include future expected air quality concentrations at the project 
location. The concentrations must then be compared to the NAAQS and the 
project will conform to the SIP only if it can be shown that the 
project does not cause or contribute to any new localized violations, 
increase the frequency or severity of any existing violations, or delay 
timely attainment of any NAAQS or any interim milestones. See 40 CFR 
93.116(a). The fact that the regulations provide that these criteria 
are met if, during the time frame of the transportation plan, (1) no 
new local violations will be created, (2) the severity or number of 
existing violations will not be increased as a result of the project, 
and (3) the project has been included in a regional emissions analysis 
that meets applicable Sec. Sec.  93.118 and/or 93.119 requirements does 
not mean that the project may delay timely attainment of the NAAQS and 
still be found to conform.
    Specifically, commenters assert that the requirement that a project 
must be included in a regional emissions analysis does not suffice to 
ensure that it will not delay timely attainment of the NAAQS, because 
the regional emissions analysis is based on the approved SIP, and EPA's 
SIP guidance does not require states to model the incremental impact of 
highway emissions in the ambient air near highways or to develop 
control strategies to remedy near-highway NAAQS violations. Commenters 
assert that only if EPA were to modify its SIP guidance accordingly 
would it be reasonable to interpret section 176(c)(1)(B)(iii) as EPA 
has done in the proposed rule. Commenters also state that section 
176(c)(1)(B)(iii) requires some remedial action to be taken if a NAAQS 
violation is projected after the attainment deadline, even if the 
project itself does not adversely affect emissions. EPA disagrees. 
First, EPA notes that any comments requesting that EPA revise its 
regulations and/or policies regarding establishment of the 
PM2.5 NAAQS, designation of PM2.5 nonattainment 
areas and development of PM2.5 SIPs are beyond the scope of 
this rulemaking. Further, the requirement that a project is included in 
a regional emissions analysis, in conjunction with the other 
requirements of Sec.  93.116(a) and the requirements of Sec.  93.123, 
is sufficient to ensure that transportation projects do not delay 
timely attainment of the NAAQS as explained below. And finally, as 
described above, the DC Circuit has already held that a project need 
not achieve additional emissions reductions needed to attain the NAAQS 
in order to conform to the SIP.
    The approved SIP for a nonattainment area contains the control 
measures and emissions projections that demonstrate

[[Page 14278]]

attainment of the NAAQS by the required attainment date, including the 
motor vehicle emissions budget that defines the upper limit of 
transportation sector emissions above which attainment could be 
delayed. Therefore, a project will not delay attainment beyond the 
required date if its transportation emissions (along with all other 
transportation emissions) are included in a conformity analysis that 
meets the SIP budgets in the attainment year and all other future 
years. Commenters point to EPA's statement in the preamble to the 2006 
PM2.5 hot-spot rule that PM2.5 SIP modeling is 
unlikely to be performed at the level of detail necessary to identify 
PM2.5 hot-spots to support their assertion that EPA cannot 
rely on the regional emissions analysis as part of the hot-spot 
analysis. However, that statement in the 2006 preamble is taken out of 
context by commenters. The original statement was part of EPA's 
explanation for not finalizing a proposed option for which projects 
need a PM10 or PM2.5 hot-spot analysis (rather 
than how the analysis is actually completed). In the 2006 rule, EPA did 
not finalize the proposed option to require hot-spot analyses only in 
the cases where the SIP identifies projects of local air quality 
concern.\47\ The 2006 statement was not, as suggested by commenters, a 
judgment on the value of the regional emissions analysis that supports 
a conformity determination. EPA continues to believe that regional 
conformity analyses are critical to meeting all of section 176(c)(1) 
requirements for project-level conformity determinations, in 
conjunction with hot-spot analyses of emissions resulting from the 
project in the local affected area along with other future expected 
emissions in that area. Rather, it only indicates EPA's view that SIP 
modeling is unlikely to identify all locations that warrant a hot-spot 
analysis.
---------------------------------------------------------------------------

    \47\ Under 40 CFR 93.123(b)(1), EPA has identified projects of 
local air quality concern that require a localized hot-spot 
analysis. These projects include all new or expanded highway 
projects that have a significant number of or a significant increase 
in diesel vehicles).
---------------------------------------------------------------------------

    Moreover, in addition to demonstrating that the project is 
consistent with the regional emissions analysis (which supports the 
budget), there can be no new local violations and the severity or 
number of existing violations cannot increase as a result of the 
project. In practice, EPA's regulations will ensure that any project 
that creates a new violation or worsens an existing violation of the 
NAAQS in the local area affected by the project (either by increasing 
the number of violations or the severity of an existing violation) will 
not be found to conform. A project will be found to conform only if it 
is demonstrated that the project will not adversely impact air quality 
concentrations in the affected local area, and has been included in a 
regional emissions analysis that meets the rule's conformity test 
requirements. Therefore, for the reasons explained above, EPA is 
finalizing the proposed regulations, which will ensure that project-
level conformity determinations will comply with all the statutory 
criteria in section 176(c)(1)(A) and (B).
    EPA has responded to other comments related to the hot-spot 
provisions at the end of this section, below.
2. Requirement for No Delay in Timely Attainment of the NAAQS
    The provisions of today's final rule clarify that a project will 
meet CAA section 176(c)(1)(B)(iii) requirements not to delay timely 
attainment as long as no new or worsened violations are predicted to 
occur, which is already required under the existing hot-spot 
requirements. While overall emissions can increase in a local area 
above those expected without a new project's implementation, a project 
will not delay timely attainment if air quality concentrations continue 
to meet federal air quality NAAQS or any violations of the NAAQS are 
not worsened.
    Furthermore, in the case where the analysis shows that air quality 
concentrations are above the NAAQS, a project would not delay timely 
attainment if air quality is improved or unchanged from what would have 
occurred without the new project's implementation. In other words, even 
where air quality concentrations are above the NAAQS, a project does 
not delay timely attainment if it improves air quality associated with 
a violation that existed prior to completion of the project, or does 
not increase such violation. In this case, the project also would still 
meet section 176(c)(1)(B)(i) and (B)(ii), in that it does not cause or 
worsen an existing violation.
    For example, suppose a hot-spot analysis is performed for a new 
highway project that is predicted to significantly increase the number 
of diesel trucks from what is expected in the local area without the 
project. A year is chosen in this example to analyze when peak 
emissions from the project are expected and future air quality is most 
likely to be impacted due to the cumulative impacts of the project and 
background emissions in the project area. Under the conformity rule, 
both as it existed and as it is amended today, the project would meet 
section 176(c)(1)(B)(iii) requirements not to delay timely attainment 
in the local project area as long as the project's new emissions do not 
create new violations or worsen existing violations in the local 
project area. Such a demonstration would examine the total impact of 
the project's new emissions in the context of the future transportation 
system, any expected growth in other emissions sources, and any 
existing or new control measures that are expected to impact the local 
project area. If the hot-spot analysis demonstrated that the proposed 
project would improve or not impact air quality, then timely attainment 
would also not be delayed from what would have occurred without the 
project. If a violation still exists with the project, but the project 
itself improves or does not change air quality, it does not delay 
timely attainment and it can conform. In contrast, if such a project 
increased emissions enough to cause a new violation or worsen an 
existing violation in the local project area, then the project would 
delay timely attainment, since worsening air quality above the NAAQS 
would impede the ability to attain in the local project area. In such a 
case, the project could not be found to conform until the new or 
worsened future violation was mitigated.
3. Requirement for No Delay in Timely Attainment of Any Required 
Interim Reductions or Milestones
    Today's final rule also ensures that a project would meet CAA 
section 176(c)(1)(B)(iii) requirements for no delay in the timely 
attainment of any required interim reductions or other milestones. EPA 
interprets ``any required interim emission reductions or other 
milestones'' to refer to CAA requirements associated with reductions 
and milestones addressed by reasonable further progress SIPs, rather 
than other reductions required for other purposes. However, EPA 
believes there is added value in referencing in section 93.116(a) the 
conformity requirement that a project be consistent with the budgets 
and control measures in any applicable SIP, not just reasonable further 
progress SIPs. Therefore, the provisions of today's final rule clarify 
that this requirement is satisfied in the local project area if a 
project is consistent with the motor vehicle emissions budget(s) and 
control measures in the applicable SIP or interim emission test(s) (in 
the absence of a SIP budget). Although such a demonstration is already 
required under the current rule, EPA's reference to the requirements in 
40 CFR 93.118 and 93.119 clarify that a project's emissions--when 
combined

[[Page 14279]]

with all other emissions from all other existing and other proposed 
transportation projects--must be consistent with any applicable 
required interim reductions and milestones.
    Today's final rule also supports the implementation of control 
measures that are relied upon in reasonable further progress 
demonstrations and could impact air quality in the local project area. 
Under today's final rule, control measures that are relied upon for 
reasonable further progress SIPs must have sufficient state and local 
commitments to be included in a regional emissions analysis or a hot-
spot analysis. If the implementation of a control measure is not 
assured, then such reductions cannot be included in the regional 
emissions analysis for the entire nonattainment or maintenance area (40 
CFR 93.122(a)) or within the local project area considered in a hot-
spot analysis (40 CFR 93.123(c)(3) and (4)), and conformity may not be 
demonstrated for a project. EPA believes that these requirements also 
ensure that ``any required interim emissions reductions or other 
milestones'' are not delayed within a local project area as a result of 
a single project's emissions.
    For example, a project may not meet CAA section 176(c)(1)(B)(iii) 
requirements if SIP control measures were not being implemented as 
expected and as a result, a project's emissions (when combined with 
expected future emissions without the SIP control measures) caused a 
new violation or worsened an existing violation in the local project 
area. In such a case, additional control measures as part of the 
conformity determination may be required in order to offset any 
emissions increases from a project.
    Today's final rule also clarifies that all CAA section 
176(c)(1)(B)(iii) requirements are met when air quality improves as a 
result of the project, e.g., an existing air quality violation that 
would have occurred without the project is estimated to be reduced or 
eliminated if the new project were implemented. EPA believes that all 
of section 176(c)(1)(B) requirements would be met in the local project 
area in such a case since the Act requires that individual projects do 
not worsen air quality or affect an area's ability to attain or achieve 
interim requirements. Certainly, if air quality improves in the local 
project area with the implementation of a new project, EPA believes 
that timely attainment and required reasonable further progress interim 
requirements are not delayed. In fact, the opposite would be true in 
such a case, since future air quality would be improved and attainment 
possibly expedited from what would have occurred without the project's 
implementation.
4. Other Comments
    EPA is including responses to other relevant comments on this 
portion of today's rule below.
    Comment: One commenter thought that based on the statutory language 
in CAA 176(c)(1)(A) and (B), promulgating rules that require 
PM2.5 emission reductions would be permissible and 
reasonable. Another commenter believed that EPA had not responded to 
the court's remand, since it was not expanding on existing conformity 
rule requirements for hot-spot analyses.
    Response: As explained above, EPA disagrees that section 176(c)(1) 
requires projects to reduce emissions. As such, EPA believes its 
interpretation of these provisions is the most reasonable one. Hot-spot 
analyses in PM2.5 (and PM10) nonattainment and 
maintenance areas are required for transportation projects of local air 
quality concern. Such projects are those highway and transit projects 
that involve significant diesel traffic, significant increases in 
diesel traffic, or significant numbers of diesel vehicles congregating 
in one location. These types of projects are unlikely to improve air 
quality in and of themselves.
    The structure of section 176(c) supports EPA's interpretation as 
the most reasonable interpretation of the statutory language. The 
conformity provisions of the CAA in 176(c)(1)(A) and (B) do not require 
that transportation activities reduce emissions, only that they be 
consistent with the purpose of the SIP. Only in the specific provision 
of 176(c)(3)(A)(iii) does the statute require transportation projects 
to ``contribute to annual emissions reductions,'' and this requirement 
applies to projects only in certain CO areas before such areas have a 
SIP, not generally to all projects. Had Congress intended for projects 
subject to sections 176(c)(1)(A) and (B) to ``contribute to annual 
emissions reductions,'' it would have included explicit language 
stating so, as it did in section 176(c)(3). See further details in our 
general rationale earlier in this section.
    Comment: One commenter requested that EPA add language to the 
conformity rule that prescribes procedures for requesting assistance 
from the air quality agency in developing offsetting emissions 
reductions, to reduce air quality concentrations at appropriate 
receptor locations to levels that attain the NAAQS on or after the 
attainment deadline.
    Response: EPA does not believe additional language is necessary 
because existing requirements adequately address the state air agency's 
involvement in developing offsetting measures. First, the existing 
regulation at 40 CFR 93.123(c)(4) states: ``CO, PM10, or 
PM2.5 mitigation or control measures shall be assumed in the 
hot-spot analysis only where there are written commitments from the 
project sponsor and/or operator to implement such measures, as required 
by Sec.  93.125(a).'' \48\ The air quality agency as well as EPA has 
the opportunity to review any such written commitments during 
interagency consultation on the conformity determination per 40 CFR 
93.105(c). Second, if offsetting measures are added to the SIP, then 
the state air quality agency would have to agree on these measures. In 
addition, the development of offsetting emissions reductions would be 
subject to the public process required for a SIP revision. Third, in 
the case where a new transportation control measure (TCM) is to be 
added to the SIP without a full SIP revision, the CAA requires the TCM 
to be developed through a collaborative process that includes the state 
air quality agency; in addition, the state air quality agency as well 
as EPA must concur before such a TCM is added to the SIP. See EPA's 
guidance, entitled, ``Guidance for Implementing the Clean Air Act 
Section 176(c)(8) Transportation Control Measure Substitution and 
Addition Provision,'' found on EPA's Web site at: http://www.epa.gov/
otaq/stateresources/transconf/policy/420b09002.pdf.
---------------------------------------------------------------------------

    \48\ In addition, the conformity rule at 40 CFR 93.101 defines 
``written commitment'' as follows: ``Written commitment for the 
purposes of this subpart means a written commitment that includes a 
description of the action to be taken; a schedule for the completion 
of the action; a demonstration that funding necessary to implement 
the action has been authorized by the appropriating or authorizing 
body; and an acknowledgement that the commitment is an enforceable 
obligation under the applicable implementation plan.'' Since these 
obligations are ``an enforceable obligation under the applicable 
implementation plan,'' state air agencies will have a role in 
ensuring that any necessary measures are properly implemented and 
enforced.
---------------------------------------------------------------------------

    Comment: One commenter thought the regulations at 40 CFR 93.116(a) 
and 93.123 are unclear regarding the specifics of performing a PM hot-
spot analysis, including whether the conformity rule requires a 
comparison of emissions from the build case with the emissions from the 
no-build case in the same future year, or whether it allows a 
comparison of the build case with emissions in the current year as the 
baseline. The commenter was concerned that if the analysis is based on 
a comparison of the build case for a future

[[Page 14280]]

year with current emissions, a project could conform even if it adds 
more vehicle trips to the project location, because the build analysis 
would include the effect of new engine control technologies and fleet 
turnover. The commenter believes that the analysis should examine the 
impacts of the project itself. Therefore, the commenter urged that the 
rule be clarified to require an estimate of future peak year emissions 
using a build/no-build analysis, which the commenter asserted would 
provide a lawful basis for assessing the impact of emissions from a 
proposed project.
    Response: This comment is beyond the scope of this rulemaking. For 
purposes of EPA's hot-spot regulations, EPA is only addressing in 
today's rule the specific issue that was remanded by the Court in 
December 2007, i.e., whether CAA section 176(c)(1)(B)(iii) applies in 
the local area affected by a project. As stated in the May 2009 
proposal, EPA did not propose or seek public comment on any other 
aspect of EPA's preexisting rules for performing hot-spot analyses 
under 40 CFR 93.123 or any other parts of the conformity rule.
    In addition, EPA has already addressed how hot-spot analyses are to 
be conducted to avoid the situation described by the commenter. In the 
original conformity rule, EPA stated its intentions for applying the 
hot-spot requirement--``that the hot-spot analysis compare 
concentrations with and without the project based on modeling of 
conditions in the analysis year.'' (58 FR 62212). The July 2004 final 
rule clarified the horizon years for hot-spot analyses. In this rule, 
EPA stated that ``[t]o 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.'' See 69 FR 40056-58 for more details on 
this rulemaking.
    Furthermore, EPA agrees that it would be inappropriate to ignore 
the future air quality impacts from building a proposed project. As 
stated above, EPA's rule requires that in the future year(s) where 
emissions are expected to be the highest, the concentrations of the 
pollutant that result from the project's emissions in combination with 
background emissions from other sources are compared to the NAAQS. 
However, this analysis is performed by examining future air quality 
impacts from a project, rather than comparing emissions from the 
project in the future to emissions in a baseline year. EPA strongly 
disagrees that the current rule can be interpreted in this way. An 
analysis under the rule does provide a lawful basis for assessing the 
impact of emissions from a proposed project, because it compares 
resulting air quality concentrations to the NAAQS, which by law are 
established by EPA through rulemaking.
    As stated above, in the case where the analysis shows that the air 
quality concentrations are greater than the NAAQS, the project may 
still be able to conform. If building the project leads to improved air 
quality concentrations over not building the project, then the project 
could still be found to conform, even if the concentrations are above 
the NAAQS. In this case, a build/no-build analysis would show that the 
project is helping to reduce concentrations, and improve air quality by 
reducing a future violation. In this case, the project neither creates 
a new violation nor worsens an existing violation, nor does it delay 
timely attainment.
    Last, it is entirely appropriate that a hot-spot analysis include 
the effects of new technologies and fleet turnover that is expected to 
occur in a future analysis year. The conformity rule has always allowed 
the future effects of federal vehicle emissions standards, fleet 
turnover, fuel programs, and other control measures to be reflected in 
hot-spot analyses when they are assured to occur, because including 
such effects provides a reasonable estimate of future emissions that is 
more accurate than not including such effects.
    Comment: One commenter opined that off-road emissions that result 
from a transportation project being built should be included in the 
hot-spot analysis as part of the background emissions, because the 
conformity regulations at 40 CFR 93.123(c) require them to be included: 
``[e]stimated pollutant concentrations must be based in the total 
emissions burden which may result from the implementation of the 
project.'' The commenter asserted that a highway project that 
facilitates additional diesel vehicles such as ocean-going vessels, 
locomotives, harborcraft, and cargo-handling equipment cannot ignore 
these significant sources of emissions that affect the air quality at 
the location of the project.
    Response: This comment is outside the scope of today's rulemaking 
for the reasons discussed above. However, EPA notes that it agrees with 
this comment. As the commenter points out, the regulations at 40 CFR 
93.123(c)(1) state: ``Estimated pollutant concentrations must be based 
on the total emissions burden which may result from the implementation 
of the project, summed together with future background 
concentrations.'' EPA agrees that if a highway project will facilitate 
additional diesel ships or locomotives, these additional non-road 
emissions must be included as part of the background concentrations in 
the hot-spot analysis. The current conformity rule also requires hot-
spot analyses to consider any emissions that are already expected to 
occur from other sources in the local project area, in addition to any 
emissions created by the project being built.
    Comment: One commenter suggested that hot-spot analyses should 
apply to existing projects, not just new projects, and that the 
language of CAA section 176(c) would support ``an ongoing duty'' to 
ensure compliance with the hot-spot rule. To the extent that the 
federal government ``engage[s] in'' or ``supports'' a facility, the 
commenter believed that a hot-spot analysis is required. For example, 
when the government provides funds for maintenance and repair of 
freight facilities, the commenter believed there should be an ongoing 
requirement to perform a hot-spot analysis.
    Response: This comment is outside the scope of today's action. EPA 
did not propose or seek comment on any revision to the hot-spot 
regulations addressing when hot-spot analyses are required. Since the 
original 1993 transportation conformity rule, EPA's hot-spot 
requirements have applied only to those projects that require project-
level conformity determinations under 40 CFR 93.102(a) and 93.104(d), 
which are those new non-exempt highway and transit projects that 
receive FHWA or FTA funding or approval. After that point, conformity 
of a project does not need to be redetermined unless one of three 
things occur: (1) The project's design concept and scope significantly 
changes; (2) three years elapse since the most recent major step to 
advance the project; or (3) a supplemental environmental document has 
been initiated for air quality purposes (40 CFR 93.104(d)). EPA has 
previously concluded that a new project-level conformity determination 
is warranted in these cases. Barring one of these cases, it is 
reasonable to conclude that conformity continues to be demonstrated, 
based on both the initial project-level conformity determination as 
well as the periodic regional conformity determination needed for the 
transportation plan and TIP, which

[[Page 14281]]

includes the project. Today's final rule addresses none of these 
requirements.
    Comment: One commenter stated that the proposed rule is 
inconsistent with EPA's definition for ``hot-spot analysis'' and the 
CAA because the proposed rule fails to require a comparison of 
localized PM2.5 concentrations to the NAAQS. The commenter 
opines that EPA's regulatory definition is consistent with the 
statutory text but the proposed rule is not in that it fails to 
expressly require that, where emissions from a highway project subject 
to hot-spot review would cause or contribute to NAAQS violations after 
the attainment deadline, approval of the project must be prohibited 
unless some remedial action is taken to avoid the NAAQS violation after 
the attainment deadline.
    The same commenter also stated that EPA's proposal is not 
consistent with the CAA because it would allow a project to conform 
even if emissions are maintained at levels that will continue to cause 
NAAQS violations after the statutory deadline.
    Response: EPA disagrees with this commenter and the description of 
the May 2009 proposal. Today's final rule does require a comparison of 
localized pollutant concentrations to the NAAQS. By requiring a 
demonstration that no new local violations are created and no existing 
violations are worsened, the regulation does require a comparison to 
the NAAQS. In addition, today's final rule would not result in the 
outcome in the example provided by commenters. As stated earlier, a 
project could not be found to conform if its emissions caused or 
contributed to a future NAAQS violation.
    In the commenter's second example, the project could be found to 
conform, since the project's emissions would not have caused or 
worsened a NAAQS violation. If a hot-spot analysis shows that air 
quality concentration levels would be the same with and without a 
project, then such a project would not be `maintaining' any NAAQS 
violation, as suggested by the commenter. Instead, such a hot-spot 
analysis would show that a project is not the cause or contributor to 
the local area's air quality problem, and consequently, the project 
would not be delaying timely attainment. See other parts of today's 
final rule preamble for rationale on similar comments.
    Comment: One commenter requested that EPA add a definition to the 
conformity rule for the term ``delay timely attainment.'' The commenter 
requested that the term be defined as follows: If emissions from a 
project are expected to cause or contribute to concentrations that are 
greater than the NAAQS at appropriate receptor locations after the 
attainment deadline, the project would fail to meet CAA 
176(c)(1)(B)(iii).
    Response: EPA does not believe it is necessary to promulgate a 
separate regulatory definition of the term ``delay timely attainment'' 
in section 93.101 of the conformity rule. Section 93.116(a) of today's 
final rule and section 93.123(c) of the existing conformity rule 
include this regulatory text, and the discussion in this preamble and 
earlier preambles to transportation conformity regulations adequately 
explain the meaning of ``delay timely attainment'' in the context of 
section 176(c)(1)(B)(iii), including how the hot-spot analysis must 
comply with that provision.
    Comment: One commenter requested that EPA define ``local area'' for 
hot-spot analysis purposes, because neither the proposed nor existing 
conformity rule clearly defines it. The commenter opined that depending 
upon the definition, the results of the analysis might be different. As 
an example, the commenter indicated that a project such as a bus 
terminal might result in increased emissions in the immediate area 
(although not enough to violate other portions of section 
176(c)(1)(B)), but may be part of a larger group of projects that would 
reduce emissions overall in a larger area.
    Response: EPA agrees that PM hot-spot analyses under the conformity 
rule must examine the air quality impacts of the PM10 and 
PM2.5 NAAQS, including the area immediately surrounding the 
project. In developing the March 2006 final PM hot-spot rule, EPA 
completed a thorough review of more than 70 studies representing a 
cross-section of available studies looking at particle concentrations 
near roadways and transit projects (71 FR 12472-12474). Many of these 
studies were completed in the types of local communities cited by the 
commenter.
    However, EPA is not defining ``local area'' in this final rule 
because the existing conformity rule, along with previous conformity 
preambles, provide the necessary information for hot-spot analyses. 
First, the rule's ``hot-spot analysis'' provisions are applied at a 
local level to an individual ``highway project'' or ``transit 
project,'' and the rule defines all three of these terms in detail (see 
40 CFR 93.101). As a result, the hot-spot requirements for individual 
projects in conformity rule sections 93.116 and 93.123 are applied 
within the local project area. Another example is the rule's definition 
of ``cause or contribute to a new violation,'' which includes the 
phrase about this requirement being met ``in an area substantially 
affected by the project.'' EPA believes that all of the conformity 
rule's hot-spot provisions provide adequate information regarding what 
is a ``local area,'' and a separate ``local area'' definition is not 
necessary or required by the December 2007 court remand.
    EPA does not believe that ``local area'' can be more specifically 
defined and still be appropriate for all projects, because projects 
where a hot-spot analysis is needed can differ in type, location, 
scale, scope, and neighboring populations. EPA believes that the 
existing regulation allows the appropriate local area to be determined 
in a hot-spot analysis.
    EPA also notes that in the commenter's example, a bus terminal 
increases emissions in the immediate area but does not violate other 
portions of section 176(c)(1)(B), i.e., this project increases 
emissions but would not create a new violation or worsen an existing 
NAAQS violation. Therefore, this project could be found to conform 
under the PM hot-spot conformity rules.
    Comment: One commenter requested that EPA define ``appropriate 
receptor location'' in section 93.123(c)(1) of the conformity rule to 
be ``locations near the project where the public has daily access and 
where exposure risks will be greatest with regard to the frequency or 
severity.'' The commenter stated that the rule should clarify that 
receptor or monitor locations should not be located outside the zone of 
observed highway impacts because at those distances no difference would 
be detected regardless of how many additional vehicles are added. The 
commenter cited examples of past PM hot-spot analyses where emissions 
impacts were examined at monitors or locations that were a mile and a 
half or more from the highway or from the residential and school 
facilities adjacent to the proposed project. The commenter stated that 
in both cases, evidence was submitted showing that highway emissions 
decrease to the level of regional background within the first 300 
meters.
    In addition, this and another commenter provided EPA with recent 
studies and data illustrating the air quality impacts of highways in 
the near-highway environment, and with data tallying the millions of 
people who live within this range as well as the number of schools 
located within it.
    Response: EPA appreciates the data that commenters provided, and 
agrees with commenters that hot-spot analyses are important to ensure 
that public health is protected. As noted in the previous response, EPA 
finalized the PM10 and PM2.5 hot-spot 
requirements based on the type of information

[[Page 14282]]

submitted by commenters (71 FR 12472-12474). However, the location of 
modeling receptors, which is addressed in 40 CFR 93.123(c), is outside 
the scope of today's final rule.
    EPA also notes that the U.S. District Court in Maryland has upheld 
the appropriateness of one of the PM qualitative hot-spot analyses 
cited by the commenter (Audubon Naturalist Society of the Central 
Atlantic States, Inc., et al v. USDOT, et al., 524 F.Supp.2d 642 (Md. 
2007), appeal dismissed without decision Environmental Defense, et al. 
v. USDOT, et al., No. 08-1107 (4th Cir., dismissed Nov. 17. 2008)).
    EPA intends to describe appropriate receptor locations in its 
forthcoming quantitative PM hot-spot guidance, which is required under 
40 CFR 93.123(b)(4). Interested parties will have an opportunity to 
comment on this document before it is finalized.\49\
---------------------------------------------------------------------------

    \49\ EPA will provide opportunity for public comment on the PM 
quantitative hot-spot guidance according to the terms of a 
settlement agreement with Environmental Defense, Natural Resources 
Defense Council, and Sierra Club. Refer to the June 22, 2007 
``Notice of proposed settlement agreement; request for public 
comment'' at 72 FR 34460.
---------------------------------------------------------------------------

    Comment: One commenter recommended that EPA require projects to 
reduce the severity and number of local 2006 PM2.5 NAAQS 
violations as a way to reduce black carbon. This commenter noted that 
in EPA's recent proposed endangerment finding for greenhouse gases, EPA 
explained that it did not include black carbon because EPA is 
addressing black carbon through its review of the primary and secondary 
PM NAAQS. This commenter cited a large body of new science explaining 
black carbon's climate forcing effect and impacts on sensitive 
ecosystems, and believed that this rule should include some specific 
requirements for black carbon.
    Response: Transportation conformity applies only to transportation-
related criteria pollutants for which a NAAQS is established and their 
precursor pollutants as described in 40 CFR 93.102(b) of the 
regulation. There is no NAAQS specifically for black carbon, therefore 
EPA lacks authority to require conformity analysis specifically for 
black carbon. To the extent that black carbon is a component of 
PM2.5 (as defined by 40 CFR 93.102(b)(1) and EPA's 
rulemakings for the development of any PM2.5 NAAQS), it is 
included as part of any conformity analysis for PM2.5.

X. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    This action is not a ``significant regulatory action'' under the 
terms of Executive Order (EO) 12866, (58 FR 51735; October 4, 1993) and 
is therefore not subject to review under the EO.

B. Paperwork Reduction Act

    This action does not impose any new information collection burden. 
The information collection requirements of EPA's existing 
transportation conformity regulations and the proposed revisions in 
today's action are already covered by EPA information collection 
request (ICR) entitled, ``Transportation Conformity Determinations for 
Federally Funded and Approved Transportation Plans, Programs and 
Projects.'' The Office of Management and Budget (OMB) has previously 
approved the information collection requirements contained in the 
existing regulations at 40 CFR Part 93 under the provisions of the 
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and has assigned OMB 
control number 2060-0561. The OMB control numbers for EPA's regulations 
in 40 CFR are listed in 40 CFR Part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an Agency 
to prepare a regulatory flexibility analysis of rules subject to notice 
and comment rulemaking requirements under the Administrative Procedure 
Act or any other statute unless the Agency certifies that the rule will 
not have a significant economic impact on a substantial number of small 
entities. Small entities include small businesses, small not-for-profit 
organizations and small government jurisdictions.
    For purposes of assessing the impacts of today's 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 that 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

    This 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 purpose of this final rule is to amend the conformity rule to 
clarify how certain highway and transit projects meet statutory 
conformity requirements for particulate matter in response to a 
December 2007 court ruling, and to update the regulation to accommodate 
revisions to the PM10 and PM2.5 NAAQS. This final 
rule 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. Thus, today's final 
rule is not subject to the requirements of sections 202 and 205 of the 
UMRA.
    This rule is also not subject to the requirements of section 203 of 
UMRA because it contains no regulatory requirements that might 
significantly or uniquely affect small governments. This rule will not 
significantly or uniquely impact small governments because it 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.

E. Executive Order 13132: Federalism

    This final rule does not have federalism implications. It will not 
have substantial direct effects on states, on the relationship between 
the national government and states, or on the distribution of power and 
responsibilities among the various levels of government, as specified 
in Executive Order 13132. The CAA requires conformity to apply in 
certain nonattainment and maintenance areas as a matter of law, and 
this action merely establishes and revises procedures for 
transportation planning entities in subject areas to follow in meeting 
their existing statutory obligations. Thus, Executive Order 13132 does 
not apply to this rule.

[[Page 14283]]

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

    This action does not have tribal implications, as specified in 
Executive Order 13175 (65 FR 67249, November 9, 2000). The CAA requires 
transportation conformity to apply in any area that is designated 
nonattainment or maintenance by EPA. This rule amends the conformity 
rule to clarify how certain highway and transit projects meet statutory 
conformity requirements for particulate matter in response to a 
December 2007 court ruling, and updates the conformity rule to 
accommodate revisions to the PM10 and PM2.5 
NAAQS. Because today's amendments to the conformity rule do not 
significantly or uniquely affect the communities of Indian tribal 
governments, Executive Order 13175 does not apply to this action.

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

    This final rule is not subject to Executive Order 13045 62 FR 
19885, April 23, 1997) because it is not economically significant as 
defined in Executive Order 12866, and because the Agency does not 
believe the environmental health or safety risks addressed by this 
action present a disproportionate risk to children.

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

    This action is not a ``significant energy action'' as defined in 
Executive Order 13211 (66 FR 18355 (May 22, 2001)), because it is not 
likely to have a significant adverse effect on the supply, 
distribution, or use of energy. It does not create a serious 
inconsistency or otherwise interfere with an action taken or planned by 
another agency regarding energy. Further, this rule is not likely to 
have any adverse energy effects because it does not raise novel legal 
or policy issues adversely affecting the supply, distribution or use of 
energy arising out of legal mandates, the President's priorities, or 
the principles set forth in Executive Orders 12866 and 13211.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 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., material specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. NTTAA directs EPA to 
provide Congress, through OMB, explanations when the Agency decides not 
to use available and applicable voluntary consensus standards.
    This action does not involve technical standards. Therefore, EPA 
did not consider the use of any voluntary consensus standards.

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

    Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes 
federal executive policy on environmental justice. Its main provision 
directs federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    EPA has determined that this final rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it increases the 
level of environmental protection for all affected populations without 
having any disproportionately high and adverse human health or 
environmental effects on any population, including any minority or low-
income population. This final rule simply amends the conformity rule to 
clarify how certain highway and transit projects meet statutory 
requirements for particulate matter in response to a December 2007 
court ruling, and updates the conformity rule to accommodate revisions 
to the PM10 and PM2.5 NAAQS.

K. Determination Under Section 307(d)

    Pursuant to CAA Section 307(d)(1)(U), the Administrator determines 
that this action is subject to the provisions of section 307(d). 
Section 307(d)(1)(U) provides that the provisions of section 307(d) 
apply to ``such other actions as the Administrator may determine.''

L. 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 prior to publication of the rule in the Federal Register. 
A major rule cannot take effect until 60 days after it is published in 
the Federal Register. This action Transportation Conformity Rule 
PM2.5 and PM10 Amendments
    Page 134 of 145 is not a ``major rule'' as defined by 5 U.S.C. 
804(2). This rule will be effective April 23, 2010.

List of Subjects in 40 CFR Part 93

    Administrative practice and procedure, Air pollution control, 
Carbon monoxide, Clean Air Act, Environmental protection, Highways and 
roads, Intergovernmental relations, Mass transportation, Nitrogen 
dioxide, Ozone, Particulate matter, Transportation, Volatile organic 
compounds.

    Dated: March 10, 2010.
Lisa P. Jackson,
Administrator.

0
For the reasons set out in the preamble, 40 CFR part 93 is amended as 
follows:

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 as follows:
0
a. By removing the definitions for ``1-hour ozone NAAQS'' and ``8-hour 
ozone NAAQS''; and
0
b. By revising the definition of ``National ambient air quality 
standards (NAAQS)''.

Sec.  93.101  Definitions.

* * * * *
    National ambient air quality standards (NAAQS) are those standards 
established pursuant to section 109 of the CAA.
    (1) 1-hour ozone NAAQS means the 1-hour ozone national ambient air 
quality standard codified at 40 CFR 50.9.
    (2) 8-hour ozone NAAQS means the 8-hour ozone national ambient air 
quality standard codified at 40 CFR 50.10.
    (3) 24-hour PM10 NAAQS means the 24-hour PM10 national 
ambient air quality standard codified at 40 CFR 50.6.
    (4) 1997 PM2.5 NAAQS means the PM2.5 national ambient 
air quality standards codified at 40 CFR 50.7.
    (5) 2006 PM2.5 NAAQS means the 24-hour PM2.5 national 
ambient air quality standard codified at 40 CFR 50.13.

[[Page 14284]]

    (6) Annual PM10 NAAQS means the annual PM10 national 
ambient air quality standard that EPA revoked on December 18, 2006.
* * * * *

Sec.  93.105  [Amended]

0
3. Section 93.105 is amended in paragraph (c)(1)(vi) by
    removing the citation ``Sec.  93.109(l)(2)(iii)'' and adding in its 
place ``Sec.  93.109(n)(2)(iii)''.

0
4. Section 93.109 is amended as follows:
0
a. In paragraph (b):
0
i. By removing the citation ``(c) through (i)'' and adding in its place 
the citation ``(c) through (k)'';
0
ii. By removing the reference ``(j)'' and adding in its place ``(l)'';
0
iii. By removing the reference ``(k)'' from the fourth sentence and 
adding in its place ``(m)'';
0
iv. By removing the reference ``(l)'' from the fifth sentence and 
adding in its place ``(n)'';
0
b. By revising paragraph (g)(2) introductory text;
0
c. By redesignating paragraph (g)(3) as (g)(4);
0
d. By adding new paragraph (g)(3);
0
e. By revising the heading of paragraph (i);
0
f. By adding the words ``such 1997'' before the words 
``PM2.5 nonattainment or maintenance areas'' in 
paragraph(i)(1);
0
g. By adding the words ``such 1997'' before the words 
``PM2.5 nonattainment and maintenance areas'' in paragraph 
(i) introductory text and paragraph (i)(2) introductory text;
0
h. By adding the words ``such 1997'' before the words 
``PM2.5 nonattainment areas'' in paragraph (i)(3);
0
i. By redesignating paragraphs (j), (k), and (l) as (l), (m), and (n), 
respectively;
0
j. In newly designated paragraph (n)(2) introductory text by removing 
the citation ``(c) through (k)'' and adding in its place the citation 
``(c) through (m)'';
0
k. In newly designated paragraph (n)(2)(iii):
0
i. By removing the citation ``(l)(2)(ii)'' and adding in its place the 
citation ``(n)(2)(ii)'';
0
ii. By removing the citation ``(l)(2)(ii)(C)'' and adding in its place 
the citation ``(n)(2)(ii)(C)'';
0
l. By adding new paragraphs (j) and (k).

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

* * * * *
    (g) * * *
    (2) In PM10 nonattainment and maintenance areas where a 
budget is submitted for the 24-hour PM10 NAAQS, the budget 
test must be satisfied as required by Sec.  93.118 for conformity 
determinations made on or after:
* * * * *
    (3) Prior to paragraph (g)(2) of this section applying, the budget 
test must be satisfied as required by Sec.  93.118 using the approved 
or adequate motor vehicle emissions budget established for the revoked 
annual PM10 NAAQS, if such a budget exists.
* * * * *
    (i) 1997 PM2.5 NAAQS nonattainment and maintenance areas. * * *
    (j) 2006 PM2.5 NAAQS nonattainment and maintenance areas without 
1997 PM2.5 NAAQS motor vehicle emissions budgets for any portion of the 
2006 PM2.5 NAAQS 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 2006 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) FHWA/FTA projects in such PM2.5 nonattainment and 
maintenance areas must satisfy the appropriate hot-spot test required 
by Sec.  93.116(a).
    (2) In such 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 for the 2006 PM2.5 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.
    (3) In such 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 for the 2006 
PM2.5 NAAQS and no adequate motor vehicle emissions budget 
from a submitted control strategy implementation plan revision or 
maintenance plan for the 2006 PM2.5 NAAQS.
    (k) 2006 PM2.5 NAAQS nonattainment and maintenance areas with motor 
vehicle emissions budgets for the 1997 PM2.5 NAAQS that cover all or a 
portion of the 2006 PM2.5 nonattainment 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 2006 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) FHWA/FTA projects in such PM2.5 nonattainment and 
maintenance areas must satisfy the appropriate hot-spot test required 
by Sec.  93.116(a).
    (2) In such 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 for the 2006 PM2.5 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.
    (3) Prior to paragraph (k)(2) of this section applying, the 
following test(s) must be satisfied:
    (i) If the 2006 PM2.5 nonattainment area covers the same 
geographic area as the 1997 PM2.5 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 1997 
PM2.5 applicable implementation plan or implementation plan 
submission;
    (ii) If the 2006 PM2.5 nonattainment area covers a 
smaller geographic area within the 1997 PM2.5 nonattainment 
or maintenance area(s), the budget test as required by Sec.  93.118 for 
either:
    (A) The 2006 PM2.5 nonattainment area using 
corresponding portion(s) of the approved or adequate motor vehicle 
emissions budgets in the 1997 PM2.5 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 1997 PM2.5 nonattainment area using the approved 
or adequate motor vehicle emissions budgets in the 1997 
PM2.5 applicable implementation plan or implementation plan 
submission. If additional emissions reductions are necessary to meet 
the budget test for the 2006 PM2.5 NAAQS in such cases, 
these emissions

[[Page 14285]]

reductions must come from within the 2006 PM2.5 
nonattainment area;
    (iii) If the 2006 PM2.5 nonattainment area covers a 
larger geographic area and encompasses the entire 1997 PM2.5 
nonattainment or maintenance area(s):
    (A) The budget test as required by Sec.  93.118 for the portion of 
the 2006 PM2.5 nonattainment area covered by the approved or 
adequate motor vehicle emissions budgets in the 1997 PM2.5 
applicable implementation plan or implementation plan submission; and 
the interim emissions tests as required by Sec.  93.119 for either: the 
portion of the 2006 PM2.5 nonattainment area not covered by 
the approved or adequate budgets in the 1997 PM2.5 
implementation plan, the entire 2006 PM2.5 nonattainment 
area, or the entire portion of the 2006 PM2.5 nonattainment 
area within an individual state, in the case where separate 1997 
PM2.5 SIP budgets are established for each state of a multi-
state 1997 PM2.5 nonattainment or maintenance area; or
    (B) The budget test as required by Sec.  93.118 for the entire 2006 
PM2.5 nonattainment area using the approved or adequate 
motor vehicle emissions budgets in the applicable 1997 PM2.5 
implementation plan or implementation plan submission.
    (iv) If the 2006 PM2.5 nonattainment area partially 
covers a 1997 PM2.5 nonattainment or maintenance area(s):
    (A) The budget test as required by Sec.  93.118 for the portion of 
the 2006 PM2.5 nonattainment area covered by the 
corresponding portion of the approved or adequate motor vehicle 
emissions budgets in the 1997 PM2.5 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 2006 PM2.5 
nonattainment area not covered by the approved or adequate budgets in 
the 1997 PM2.5 implementation plan, the entire 2006 
PM2.5 nonattainment area, or the entire portion of the 2006 
PM2.5 nonattainment area within an individual state, in the 
case where separate 1997 PM2.5 SIP budgets are established 
for each state in a multi-state 1997 PM2.5 nonattainment or 
maintenance area.
* * * * *

0
5. Section 93.116 is amended by revising paragraph (a) to read as 
follows:

Sec.  93.116  Criteria and procedures: Localized CO, PM10, and PM2.5 
violations (hot-spots).

    (a) This paragraph applies at all times. The FHWA/FTA project must 
not cause or contribute to any new localized CO, PM10, and/
or PM2.5 violations, increase the frequency or severity of 
any existing CO, PM10, and/or PM2.5 violations, 
or delay timely attainment of any NAAQS or any required interim 
emission reductions or other milestones in CO, PM10, and 
PM2.5 nonattainment and maintenance areas. This criterion is 
satisfied without a hot-spot analysis in PM10 and 
PM2.5 nonattainment and maintenance areas for FHWA/FTA 
projects that are not identified in Sec.  93.123(b)(1). This criterion 
is satisfied for all other FHWA/FTA projects in CO, PM10 and 
PM2.5 nonattainment and maintenance areas if it is 
demonstrated that during the time frame of the transportation plan 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, 
and the project has been included in a regional emissions analysis that 
meets applicable Sec. Sec.  93.118 and/or 93.119 requirements. 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.
* * * * *

Sec.  93.118  [Amended]

0
6. Section 93.118 is amended in paragraph (a) by removing the citation 
``Sec.  93.109(c) through (l)'' and adding in its place ``Sec.  
93.109(c) through (n)''.

0
7. Section 93.119 is amended as follows:
0
a. In paragraph (a), by removing the citation ``Sec.  93.109(c) through 
(l)'' and adding in its place ``Sec.  93.109(c) through (n)''; and
0
b. By revising paragraph (e)(2).

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

* * * * *
    (e) * * *
    (2) The emissions predicted in the ``Action'' scenario are not 
greater than:
    (i) 2002 emissions, in areas designated nonattainment for the 1997 
PM2.5 NAAQS; or
    (ii) Emissions in the most recent year for which EPA's Air 
Emissions Reporting Requirements (40 CFR Part 51, Subpart A) requires 
submission of on-road mobile source emissions inventories, as of the 
effective date of nonattainment designations for any PM2.5 
NAAQS other than the 1997 PM2.5 NAAQS.
* * * * *

Sec.  93.121  [Amended]

0
8. Section 93.121 is amended:
0
a. In paragraph (b) introductory text by removing the citation ``Sec.  
93.109(l)'' and adding in its place ``Sec.  93.109(n)'';
0
b. In paragraph (c) introductory text by removing the citation ``Sec.  
93.109(j) or (k)'' and adding in its place ``Sec.  93.109(l) or (m)''.

[FR Doc. 2010-5703 Filed 3-23-10; 8:45 am]
BILLING CODE 6560-50-P