[Federal Register Volume 70, Number 87 (Friday, May 6, 2005)]
[Rules and Regulations]
[Pages 24280-24292]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-9086]
[[Page 24279]]
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Part VI
Environmental Protection Agency
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40 CFR Part 93
Transportation Conformity Rule Amendments for the New PM2.5
National Ambient Air Quality Standard: PM2.5 Precursors;
Final Rule
Federal Register / Vol. 70, No. 87 / Friday, May 6, 2005 / Rules and
Regulations
[[Page 24280]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 93
[Docket No. OAR-2003-0049; FRL-7908-3]
RIN 2060-AN03
Transportation Conformity Rule Amendments for the New PM2.5
National Ambient Air Quality Standard: PM2.5 Precursors
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This final rule adds the following transportation-related
PM2.5 precursors to the transportation conformity
regulations: nitrogen oxides (NOX), volatile organic
compounds (VOCs), sulfur oxides (SOX), and ammonia
(NH3). The final rule specifies when each of these
precursors must be considered in conformity determinations in
PM2.5 nonattainment and maintenance areas before and after
PM2.5 state air quality implementation plans (SIPs) are
submitted. Today's action also makes a technical correction to a cross-
reference of the U.S. Department of Transportation's (DOT) planning
regulations in the public consultation procedures of the conformity
rule. The Clean Air Act requires federally supported highway and
transit projects to be consistent with (``conform to'') the purpose of
a SIP. EPA has consulted with DOT on the development of this final rule
and DOT concurs with its content.
EFFECTIVE DATE: June 6, 2005.
ADDRESSES: Materials relevant to this rulemaking are in Public Docket
I.D. No. OAR-2003-0049 located at the Air Docket, Environmental
Protection Agency, Mailcode: 6102T, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460; phone: 202-566-1742. For more information about
accessing information from the docket, see Section I.B. of the
SUPPLEMENTARY INFORMATION section.
FOR FURTHER INFORMATION CONTACT: Rudy Kapichak, State Measures and
Conformity Group, Transportation and Regional Programs Division, U.S.
Environmental Protection Agency, 2000 Traverwood Road, Ann Arbor, MI
48105, e-mail address: kapichak.rudolph@epa.gov, telephone number:
(734) 214-4574, fax number 734-214-4052; or Angela Spickard, State
Measures and Conformity Group, Transportation and Regional Programs
Division, U.S. Environmental Protection Agency, 2000 Traverwood Road,
Ann Arbor, MI 48105, e-mail address: spickard.angela@epa.gov, telephone
number: (734) 214-4283, fax number 734-214-4052.
SUPPLEMENTARY INFORMATION: The contents of this preamble are listed in
the following outline:
I. General Information
II. Background
III. PM2.5 Precursors
IV. Technical Correction to Public Consultation Procedures
V. How Does Today's Final Rule Affect Conformity SIPs?
VI. 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 conformity rule. Other
types of entities not listed in the table could also be regulated. To
determine whether your organization is regulated by this action, you
should carefully examine the applicability requirements in Sec. 93.102
of the transportation conformity rule. If you have questions regarding
the applicability of this action to a particular entity, consult the
persons listed in the preceding FOR FURTHER INFORMATION CONTACT
section.
B. How Can I Get Copies of This Document?
1. Docket. Materials relevant to this rulemaking are in Public
Docket I.D. No. OAR-2003-0049. The official public docket consists of
the documents specifically referenced in this action, any public
comments received, and other information related to this action.
Although a part of the official docket, the public docket does not
include Confidential Business Information (CBI) or other information
whose disclosure is restricted by statute. The official public docket
is the collection of materials that is available for public viewing at
the Air Docket in the EPA Docket Center, (EPA/DC) EPA West, Room B102,
1301 Constitution Ave., NW., Washington, DC. The Docket telephone
number is (202) 566-1742. The EPA Docket Center Public Reading Room is
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding
legal holidays. The telephone number for the Public Reading Room is
(202) 566-1744. You may have to pay a reasonable fee for copying docket
materials.
2. Electronic Access. You may access this Federal Register document
electronically through EPA's Transportation Conformity Web site at
http://www.epa.gov/otaq/transp/traqconf.htm. You may also access this
document electronically under the Federal Register listings at http://www.epa.gov/fedrgstr/.
An electronic version of the public docket is available through
EPA's electronic public docket and comment system, EPA Dockets. You may
use EPA Dockets at http://www.epa.gov/edocket/ to view public comments,
access the index listing of the contents of the official public docket,
and to access those documents in the public docket that are available
electronically. Although not all docket materials may be available
electronically, you may still access any of the publicly available
docket materials through the docket facility identified in Section
I.B.1. Once in the EPA electronic docket system, select ``search,''
then key in the appropriate docket identification number.
II. Background
A. What Is Transportation Conformity?
Transportation conformity is required under Clean Air Act section
176(c) (42 U.S.C. 7506(c)) to ensure that federally
[[Page 24281]]
supported highway and transit project activities are consistent with
(``conform to'') the purpose of the state air quality implementation
plan (SIP). Conformity currently applies to areas that are designated
nonattainment, and those redesignated to attainment after 1990
(``maintenance areas'' with plans developed under Clean Air Act section
175A) for the following transportation-related criteria pollutants:
ozone, particulate matter (PM2.5 and PM10),\1\
carbon monoxide (CO), and nitrogen dioxide (NO2). Conformity
to the purpose of the SIP means that transportation activities will not
cause new air quality violations, worsen existing violations, or delay
timely attainment of the relevant national ambient air quality
standards (NAAQS or ``standards'').
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\1\ Section 93.102(b)(1) of the conformity rule 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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B. What Is the History of the Transportation Conformity Rule?
EPA's transportation conformity rule establishes the criteria and
procedures for determining whether transportation activities conform to
the SIP. EPA first promulgated the transportation conformity rule on
November 24, 1993, (58 FR 62188) and subsequently published a
comprehensive set of amendments on August 15, 1997, (62 FR 43780) that
clarified and streamlined language from the 1993 rule. EPA has made
other smaller amendments to the rule both before and after the 1997
amendments.
On July 1, 2004, EPA published a final rule (69 FR 4004) that
amended the conformity rule to accomplish three objectives. The final
rule:
Provided conformity procedures for state and local
agencies under the new ozone and PM2.5 air quality
standards;
Incorporated existing EPA and U.S. Department of
Transportation (DOT) federal guidance into the conformity rule
consistent with a March 2, 1999, U.S. Court of Appeals decision; and
Streamlined and improved the conformity rule.
The July 1, 2004, final conformity rule incorporated most of the
provisions from the November 5, 2003, proposal for conformity under the
new ozone and PM2.5 standards (68 FR 62690). EPA is
conducting its conformity rulemakings for the new standards in the
context of EPA's broader strategies for implementing the new ozone and
PM2.5 standards.
The July 2004 final rule also incorporated all of the amendments
resulting from a separate June 30, 2003, proposal (68 FR 38974). This
proposal addressed the March 2, 1999, court ruling by the U.S. Court of
Appeals for the District of Columbia Circuit (Environmental Defense
Fund v. EPA, et al., 167 F. 3d 641, D.C. Cir. 1999), and incorporated
existing federal guidance consistent with the court decision.
Most recently, on December 13, 2004, EPA published in the Federal
Register a supplemental notice of proposed rulemaking to the November
5, 2003, new standards conformity proposal entitled, ``Options for
PM2.5 and PM10 Hot-Spot Analyses in the
Transportation Conformity Rule Amendments for the New PM2.5
and Existing PM10 National Ambient Air Quality Standards''
(69 FR 72140). In response to substantial comments received on the
November 2003 proposal, EPA, in consultation with DOT, proposed
additional options for PM2.5 and PM10 hot-spot
requirements and requested comment on them as well as on the options
presented in the November 2003 proposal. Subsequently, EPA extended the
public comment period for this supplemental proposal, to January 27,
2005. EPA has not yet taken final action on the December 13, 2004
supplemental proposal. We are currently reviewing the public comments
received on the supplemental proposal and will be issuing a final rule
in the near future.
C. Why Are We Issuing This Final Rule?
In the November 5, 2003, proposal, EPA proposed options for
addressing PM2.5 precursors in the conformity process.
However, EPA did not finalize PM2.5 precursor requirements
in the subsequent July 1, 2004, final rule because EPA had not proposed
a broader PM2.5 implementation rule to seek comment on
options for addressing PM2.5 precursors in the New Source
Review program and in SIP planning activities such as reasonable
further progress plans, attainment demonstrations, reasonably available
control technology (RACT) requirements, and reasonably available
control measures (RACM) analyses. At that time, EPA believed that it
would have been inappropriate to select a final option for precursors
in transportation conformity determinations prior to the development of
the precursor options in the broader PM2.5 implementation
rule proposal. While EPA has not yet proposed the PM2.5
implementation strategy, EPA has moved ahead with PM2.5
designations and this action has caused us to re-evaluate the need to
defer finalization of the PM2.5 precursor requirements for
transportation conformity until the implementation rule is proposed.
Our re-evaluation is based on the fact that the one-year conformity
grace period began on April 5, 2005, the effective date of the
designations. EPA believes that it is crucial that PM2.5
nonattainment areas be aware of the requirements for PM2.5
precursors at the beginning of the one-year grace period in order to
facilitate completion of all necessary work to determine conformity by
the end of the grace period for all applicable precursors. Therefore,
EPA has decided to finalize the transportation conformity requirements
for PM2.5 precursors in advance of proposing the
PM2.5 implementation rule. Although the implementation rule
has not yet been proposed, on-going consideration of issues related to
precursors in the implementation rule have been coordinated with
development of this final rule.
EPA's implementation strategy for the PM2.5 standard
will include options for addressing PM2.5 precursors in
other air quality planning programs (e.g., New Source Review for
stationary sources). The public will have the opportunity to comment on
these options during the comment period for that rulemaking once it is
published in Federal Register.
In today's final rule, EPA addresses all public comments on the
PM2.5 precursor options included in the November 2003
conformity proposal that were received during the comment period for
that rulemaking. The comment period for the November 2003 conformity
proposal ended on December 22, 2003.
Today's final rule should not be interpreted as prejudging our
decision on the PM2.5 precursor requirements that will soon
be proposed in the PM2.5 implementation rulemaking. Our
final rule for the implementation proposal will reflect how
PM2.5 precursors should best be considered in other air
quality planning programs and the comments received on that proposal.
While EPA's final decisions on PM2.5 precursors must be
legally consistent, EPA could take differing positions with respect to
various precursors in other programs as appropriate to the programmatic
needs, legal requirements and pollution sources relevant to the
differing programs.
EPA notes, however, that if in the future we change our legal
rationale for considering PM2.5 precursors among the various
air quality planning programs from the positions currently under
consideration as a result of comments received on the PM2.5
implementation strategy proposal, such changes could necessitate a
subsequent revision to the transportation conformity rule. In the
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case where an amendment to the conformity regulations is needed to
reflect an alternative approach to considering PM2.5
precursors, EPA would conduct such a revision through full public
notice and comment rulemaking.
DOT is our federal partner in implementing the transportation
conformity regulations. We have consulted DOT in developing this final
rule and DOT concurs with its content.
D. How Does This Final Rule Affect the One-Year Conformity Grace
Period?
As explained in the July 1, 2004, final rule that addresses the
conformity requirements for the 8-hour ozone and PM2.5
standards (69 FR 40004), conformity applies one year after the
effective date of EPA's initial nonattainment designation for a given
pollutant and standard. On January 5, 2005 (70 FR 943), EPA designated
areas as attainment and nonattainment for the PM2.5 air
quality standard. These designations became effective on April 5, 2005,
90 days after EPA's published action in the Federal Register.
Therefore, conformity for the PM2.5 standard will apply on
April 5, 2006.
Today's final rule does not change the one-year conformity grace
period for any area recently designated nonattainment for the
PM2.5 standard. On April 5, 2006, metropolitan
PM2.5 nonattainment areas must have in place a
transportation plan and transportation improvement program (TIP) that
conforms in accordance with the PM2.5 precursor requirements
finalized by today's action and the requirements previously finalized
by the July 1, 2004, rulemaking. See the July 1, 2004, final rule (69
FR 40008 through 40014) for more information on the implementation of
the one-year conformity grace period in newly designated
PM2.5 nonattainment areas.
III. PM2.5 Precursors
A. Description of the Final Rule
Today's final rule identifies four transportation-related
PM2.5 precursors--nitrogen oxides (NOX), volatile
organic compounds (VOCs), sulfur oxides (SOX), and ammonia
(NH3)--for consideration in the conformity process in
PM2.5 nonattainment and maintenance areas. Once a
PM2.5 SIP is submitted, a regional emissions analysis would
be required for a given precursor if the SIP establishes an adequate or
approved budget for that particular precursor.
The November 5, 2003, notice of proposed rulemaking contained two
options for addressing PM2.5 precursors in conformity
determinations made before a SIP is submitted and emissions budgets are
found adequate or approved. EPA is finalizing a modified version of the
proposed options in this final rule. Specifically, a regional emissions
analysis is required for NOX as a PM2.5 precursor
in all PM2.5 nonattainment areas, unless the head of the
state air agency and the EPA Regional Administrator make a finding that
NOX is not a significant contributor to the PM2.5
air quality problem in a given area. Regional emissions analyses are
not required for VOC, SOX or ammonia before an adequate or
approved SIP budget for such precursors is established, unless the head
of the state air agency or EPA Regional Administrator makes a finding
that on-road emissions of any of these precursors is a significant
contributor. Prior to EPA finding the budgets from the submitted
PM2.5 SIP adequate or approving the PM2.5 SIP,
the MPO and DOT will document in their conformity determinations that a
regional emissions analysis has not been conducted for NOX
when EPA and the state air agency have determined NOX to be
insignificant. The regulatory text for this final rule can be found in
Sec. Sec. 93.102(b)(2)(iv) and (v) and 93.119(f)(9) and (10).
A state air agency and/or EPA finding of significance or
insignificance (a ``significance finding'') for a PM2.5
precursor will be based on criteria similar to the general criteria for
insignificance of motor vehicle emissions in Sec. 93.109(k) of the
conformity rule. Specifically, the following criteria will be
considered in making significance or insignificance findings for
PM2.5 precursors: The contribution of on-road emissions of
the precursor to the total 2002 baseline SIP inventory; the current
state of air quality for the area; the results of speciation monitoring
for the area; the likelihood that future motor vehicle control measures
will be implemented for a given precursor; and projections of future
on-road emissions of the precursor. Determining the significance or
insignificance of motor vehicle emissions in a given area will be
conducted on a case-by-case basis.
Significance and insignificance findings will be made only after
discussions among the interagency consultation partners for the
PM2.5 nonattainment area. These discussions should include a
review of the available data being considered to support the
significance finding. Interagency consultation also ensures that all of
the relevant agencies are aware that such a finding is being
considered. It is important to provide transportation agencies with
adequate notice of which, if any, precursors they may need to address
in conformity analyses. A significance finding will be made through a
letter from the state air agency or EPA regional office to the relevant
state and local air quality and transportation agencies, MPO(s), DOT
and EPA (in the case of a state air agency finding). An insignificance
finding will be made through either letters from the state air agency
and the EPA regional office or a letter co-signed by the state air
agency and the EPA regional office to the relevant state and local air
quality and transportation agencies, MPO(s) and DOT.
EPA notes that any significance or insignificance finding made
prior to EPA's adequacy finding for budgets in a SIP, or EPA's approval
of the SIP, should not be viewed as the ultimate determination of the
significance of precursor emissions in a given area. State and local
agencies may find through the SIP development process that emissions of
one or more precursors are significant, even if a precursor had
previously been considered insignificant. In such a case, the
PM2.5 SIP would establish a motor vehicle emissions budget
for that precursor and a regional emissions analysis for that precursor
would be included in subsequent conformity determinations.
Alternatively, state and local agencies may find through the SIP
development process that emissions of one or more precursors are
insignificant even if a precursor had previously been considered
significant. In such a case, the PM2.5 SIP would not
establish a motor vehicle emissions budget for that precursor and a
regional emissions analysis for that precursor would not be necessary
in subsequent conformity determinations.
To calculate emission factors for PM2.5 precursors,
areas must use the latest EPA-approved motor vehicle emissions factor
model (currently MOBILE6.2 for all states except California).
PM2.5 nonattainment and maintenance areas in California must
use EMFAC2002 or a more recently EPA-approved model. It should be noted
that EMFAC2002 does not calculate emissions factors for ammonia.
However, EPA understands that California is developing a methodology
for estimating ammonia emissions from on-road vehicles. It is
anticipated that this methodology will be completed prior to the end of
the one-year conformity grace period. However, as a practical matter,
conformity for ammonia would not be required in California until there
is an acceptable method for estimating such
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emissions, because a method would be needed to estimate current or
future ammonia emissions for either a significance finding or SIP motor
vehicle emissions budget.
B. Rationale for This Final Rule
Section 176(c)(1)(B) of the Clean Air Act requires that federal
funding and approval be given only to transportation activities that
are consistent with state and local air quality goals. To fulfill this
requirement with respect to PM2.5, EPA is requiring that
transportation conformity determinations consider PM2.5
precursors if they are significant contributors to an area's
PM2.5 air quality problem.
Today's final rule incorporates NOX, VOCs,
SOX, and ammonia as possible transportation-related
PM2.5 precursors because all of these precursors are emitted
from on-road motor vehicles. Based on data collected from monitoring
sites in the national speciation trends network,\2\ secondary particles
from precursors commonly account for over half of the total fine
particle mass from all emissions sources measured at these sites.
Therefore, we expect that areas may need to address on-road emissions
of relevant precursors (i.e., NOX, VOC, SOX and
ammonia) in their SIPs and in conformity.
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\2\ The speciation trends network consists of over 50 monitoring
sites in urban areas and provides nationally consistent data on
PM2.5 constituents by type (i.e., ``speciated'')
including nitrates, elemental carbon, organic carbon and sulfates.
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The final rule allows for the consideration of the four precursors
in conformity prior to PM2.5 SIPs when such precursors are
significant: NOX is considered significant in the absence of
a finding; VOCs, SOX and ammonia must be found significant
to be included. In finalizing this rule EPA attempted to strike a
balance between: (1) Expeditiously addressing transportation-related
emissions that could exacerbate the PM2.5 air quality
problem before a SIP is established, and (2) targeting conformity
requirements in PM2.5 areas in an efficient and reasonable
manner.
EPA based its decision on a number of factors. For example, EPA
considered the environmentally conservative nature of requiring
conformity determinations for all four precursors prior to the
submission of a SIP unless a finding is made that on-road emissions of
a precursor or precursors is insignificant, rather than only for
NOX. Requiring that all four precursors be addressed in
conformity prior to the submission of a SIP may be a more
environmentally protective approach to meeting the Clean Air Act's
conformity requirements because any significant precursors would
automatically be addressed without the need for a significance finding
to be made by the state air agency or the EPA regional office. On the
other hand, requiring significance findings for the precursors VOCs,
SOX and ammonia better accounts for regional variability in
air quality and better targets resources to the precursors that are
most important in an individual area. Also, requiring significance
findings for these three precursors could help areas avoid adopting on-
road control measures to address a particular precursor before a SIP is
submitted that ultimately prove to be unnecessary after a SIP is
developed, if emissions of the targeted precursor are ultimately found
to be insignificant. In addition, EPA also considered with respect to
each precursor the chemistry of secondary particle formation, the
results of speciated air quality monitoring and on-road emissions
inventory data. In addition to the information provided below, the
November 2003 notice of proposed rulemaking contains a more detailed
discussion of speciated air quality data and on-road emissions data (68
FR 62706 through 62708). Please refer to the notice of proposed
rulemaking for additional details.
Sulfur dioxide. While speciated air quality data show that sulfate
is a relatively significant component (e.g., ranging from nine to 40
percent) of PM2.5 mass in all regions of the country,
emissions inventory data and projections show that on-road emissions of
SOX constitute a ``de minimis'' (i.e., extremely small)
portion of total SOX emissions. Emissions inventory data for
1999 for the 372 potential PM2.5 nonattainment counties for
PM2.5 (based on 1999-2001 air quality data) show that on-
road sources were responsible for only two percent of total
SOX emissions. By comparison, fuel combustion sources (e.g.,
electric utility and industrial combustion of coal and oil) contributed
approximately 88 percent of the SOX emissions in 1999 in
these same counties.
Furthermore, EPA has already adopted two regulations that will
greatly reduce emissions of SOX from on-road sources by the
time such regulations are both in full effect in 2009. First, in 2004
the low sulfur gasoline program began to be phased in and will be fully
effective in 2007 (February 10, 2000, 65 FR 6697). This regulation will
reduce the sulfur content of gasoline by approximately 90 percent when
fully effective.\3\ Second, in 2006 the low sulfur diesel program will
begin to be phased in and will be fully effective by 2009 (January 18,
2001, 66 FR 5001). This regulation will reduce the sulfur content of
diesel fuel by approximately 97 percent nationally when fully
effective.
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\3\ In addition, California has adopted its own rule which
addresses the sulfur content of gasoline in that State. California's
regulation is similar in stringency to the Federal regulation.
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Projections of on-road emissions of SO2 in 2020 indicate
that on-road sources will be responsible for less than one percent of
the total SO2 emissions in 2020 in the 372 potential
PM2.5 nonattainment counties (based on 1999-2001 air quality
data).\4\ These projections confirm that the implementation of the fuel
regulations discussed above will ensure that as a general matter
SO2 emissions from on-road sources remain at insignificant
levels in all areas. Therefore, states are not required to include
SOX in conformity determinations prior to submission of a
SIP unless the state air agency or EPA regional office makes a finding
that on-road emissions of SOX are a significant contributor
to an area's PM2.5 problem. If a state determines through
its SIP development process that on-road emissions of SOX
are significant and the SIP includes an adequate or approved emissions
budget for SOX, then future conformity determinations will
be required to include a regional emissions analysis for
SOX.
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\4\ EPA 420-R-00-020, October 2002, ``Procedures for Developing
Base Year and Future Year Mass and Modeling Inventories for the
Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel
(HDD) Rulemaking.''
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Nitrogen oxides. Based on a review of speciated monitoring data
analyses, nitrate concentrations vary significantly across the country.
For example, in some southeastern locations, annual average nitrate
levels range from six to eight percent of total PM2.5 mass,
whereas nitrate comprises 40 percent or more of PM2.5 mass
in certain California locations. Nitrate formation is favored by the
availability of ammonia, low temperatures, and high relative humidity.
Nitrate formation also depends upon the amount of nearby SO2
emissions because ammonia reacts preferentially with SO2
over NOX (i.e., ammonia first reacts to form ammonium
sulfate and then reacts to form ammonium nitrate).
The sources of NOX are numerous and widespread,
including motor vehicles, power plants, and many other combustion
activities. We believe these source categories and the potential for
significant impacts on air quality exist in many nonattainment areas.
The analysis of speciated air quality data
[[Page 24284]]
and the discussion of emission inventory data in the November 2003
transportation conformity notice of proposed rulemaking provide an
appropriate basis for deciding that states must include NOX
in conformity determinations made before SIPs are submitted and
emissions budgets are found adequate or approved, unless the state air
agency and the EPA regional office find that on-road emissions of
NOX are not a significant contributor to the area's
PM2.5 problem.
EPA believes that requiring both the state air agency and the EPA
regional office make an insignificance finding for NOX is
warranted because in this rulemaking EPA has initially determined that
NOX is a significant precursor for all PM2.5
nonattainment areas. Additionally, all other insignificance findings
require both state air agency and EPA regional office action because
they are made through either a motor vehicle emission budget adequacy
finding or a SIP approval as required by Sec. 93.109(k) of the
conformity regulation. Therefore, based on the reasons stated above,
EPA believes that it is necessary that both the state air agency and
the EPA regional office make a finding that on-road emissions of
NOX are an insignificant contributor to an area's
PM2.5 air quality problem prior to the submission of a SIP.
A finding made by both agencies provides assurance that on-road
emissions of NOX are in fact insignificant contributors to
an area's PM2.5 air quality problem and therefore may be
omitted from conformity determinations prior to the submission of a SIP
for the area. After a PM2.5 SIP is submitted, conformity
determinations will be required for on-road emissions of NOX
if the SIP includes emissions budgets that are found adequate or are
approved.
Volatile Organic Compounds. In 2003, EPA estimates that on-road
motor vehicles accounted for 28 percent of total VOCs nationwide.
Carbonaceous particles, which result, in part, from reactions involving
VOCs, account for 25-70% of constructed fine particle mass measured at
specific Speciation Trends Network sites. The highest percentages of
carbonaceous particles tend to be in the western United States, while
the lowest percentages tend to be in the eastern United States.
Although research clearly indicates that VOCs can contribute to the
formation of carbonaceous secondary PM2.5 compounds, the
current science is still incomplete in its understanding of the
fraction of particulate organic compounds that began as VOCs. A major
reason for this existing deficiency is the varying degrees of
volatility of organic compounds, as well as our inability to model
collectively the reactivity of these different groups of compounds. For
example, there are highly reactive volatile compounds with six or fewer
carbon atoms that indirectly contribute to PM formation through
reaction with oxidizing compounds such as the hydroxyl radical and
ozone. There are also semi-volatile compounds with between seven and 24
carbon atoms that can exist in particle form and can readily be
oxidized to form other low volatility compounds. Finally, high
molecular weight organic compounds (with 25 carbon atoms or more and
low vapor pressure) are emitted directly as primary organic particles
and exist primarily in the condensed phase at ambient temperatures. For
this reason, these high molecular weight organic compounds are
generally considered to be primary particles and not VOCs. The relative
importance of each of these groups of organic compounds in the
formation of organic particles varies from area to area. In addition,
the contribution of on-road source emissions to each of these three
groups of organic compounds may also vary from area to area.
Current scientific and technical information clearly shows that
carbonaceous material is a significant fraction of total
PM2.5 mass in most areas, and that certain aromatic VOC
emissions such as toluene, xylene, and trimethyl-benzene are precursors
to the formation of secondary PM2.5 (secondary organic
aerosols). However, while significant progress has been made in
understanding the role of gaseous organic material in the formation of
organic PM, this relationship is complex and requires further research
and technical tools to determine the extent of the contribution of
specific VOC compounds to organic PM mass, prior to EPA being able to
determine the extent of the contribution of VOCs to nonattainment
problems in all PM2.5 areas.
Additional research is also needed to determine the sources of VOC
emissions that contribute most to PM2.5 air quality issues.
For example, analysis of air quality samples collected in Pittsburgh,
Pennsylvania from 1998 through 2003 indicate that approximately half of
the secondary organic aerosol in Pittsburgh may be attributable to
biogenic sources (e.g., trees) as opposed to anthropogenic sources
(i.e., man-made sources such as power plants and motor vehicles).
Similarly, analysis of air quality samples collected in Atlanta,
Georgia from 1998 through 2003 indicate that as much as 80 percent of
the secondary organic aerosol may be attributable to biogenic sources.
These data \5\ are significant because biogenic emissions cannot be
controlled. In addition, EPA believes that in some PM2.5
nonattainment areas, particularly during seasons with high
photochemical activity, a significant amount of the secondary organic
aerosol may be due to biogenic emissions as opposed to anthropogenic
emissions of VOCs, as evidenced by the data from Pittsburgh and
Atlanta.
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\5\ Data from the PM Supersites Program documented in a
September 2004 summary response entitled, ``Policy Relevant Science
Questions Regarding PM--Precursors,'' Prepared by Spyros Pandis,
CMU; David Allen, University of Texas at Austin; Armistead (Ted)
Russell, Georgia Institute of Technology; and Paul A. Solomon, U.S.
EPA, ORD. This document can be found in the docket for today's
rulemaking.
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EPA acknowledges that analytical tools are evolving to enable areas
to adequately model the contribution of VOCs to PM2.5
formation. Researchers in the field anticipate that within the next
five years the ability of models to simulate various components of
PM2.5 will improve greatly, as will their ability to
estimate the effectiveness of various control measures. These model
improvements are particularly significant for secondary organic
aerosols and biogenic and anthropogenic emissions of VOCs. However,
until such model improvements are made and our understanding of VOC
secondary particle formation improves, EPA believes it is not
appropriate to require regional conformity analyses for VOCs in
PM2.5 nonattainment areas prior to the submission of a
PM2.5 SIP and emissions budgets for VOCs being found
adequate or approved, unless the state air agency or EPA regional
office finds that VOCs are a significant contributor to an area's
PM2.5 problem. If a state determines through its SIP
development process that on-road emissions of VOCs are significant and
the SIP includes an adequate or approved emissions budget for VOCs,
then future conformity determinations will be required to include a
regional emissions analysis for VOCs.
Ammonia. We believe a case-by-case approach is also appropriate for
ammonia because there is sufficient uncertainty about emissions
inventories and about the potential efficacy of control measures from
location to location. Reductions of ammonia may be effective primarily
in areas where nitric acid is in abundance and ammonia is the limiting
factor to ammonium nitrate formation (ammonium nitrate is a type of
[[Page 24285]]
particulate matter). Although ammonia reductions may be appropriate in
selected locations, in other locations such reductions may lead to
increased atmospheric acidity, exacerbating acidic deposition problems.
In other words, states should evaluate the benefits of including
ammonia in conformity determinations prior to the submission of SIPs
and emissions budgets being found adequate or approved. Therefore,
states are not required to include ammonia in conformity determinations
prior to submission of a SIP unless the state air agency or EPA
regional office makes a finding that on-road emissions of ammonia are a
significant contributor to an area's PM2.5 problem. If a
state determines through its SIP development process that on-road
emissions of ammonia are significant and the SIP includes an adequate
or approved emissions budget for ammonia, then future conformity
determinations will be required to include a regional emissions
analysis for ammonia.
C. Response to Comments
1. Required Precursors
Two comments received on the November 5, 2003, proposed rulemaking
indicated support for identifying NOX, VOCs, SOX
and ammonia as potential transportation-related PM2.5
precursors. No commenters were opposed to identifying all of these as
potential precursors.
EPA received a number of comments on the proposed options for
addressing precursors during the period before PM2.5 SIPs
are submitted and emissions budgets are found adequate or approved. The
majority of commenters supported option 2 included in the November 2003
proposal. Option 2 would have required significance findings for any of
the four precursors to be analyzed in conformity determinations prior
to EPA finding emissions budgets in a PM2.5 SIP adequate or
EPA's approval of that SIP. Some commenters that supported option 2
believed that limited resources would be best used by determining which
precursors contribute significantly to an area's air quality problem
before conformity for those precursors was required. A number of
commenters also supported the proposed option 1. Option 1 would have
required NOX and VOCs to be analyzed in conformity
determinations prior to the submission of PM2.5 SIPs unless
one or both precursors was determined to be insignificant. This option
also would not have required SOX or ammonia to be analyzed
for conformity prior to a submitted SIP unless one or both precursors
was found significant. Two supporters of option 1 believed sufficient
air quality data exists for their areas to support requiring analysis
of NOX and VOCs in conformity determinations prior to the
submission of a PM2.5 SIP.
One commenter recommended that to properly implement the Clean Air
Act in all PM2.5 areas, conformity determinations should be
required for all four precursors prior to the submission of a
PM2.5 SIP unless a precursor was found to be insignificant.
This commenter believed that it would be unreasonable to allow an area
to opt out of conducting an analysis by default for a precursor that
could be responsible for a large portion of PM2.5.
Additionally, two commenters indicated that SOX should be
addressed in conformity determinations prior to submission of a
PM2.5 SIP unless it is found to be insignificant. One
commenter stated that ammonia should be included in conformity
determinations as soon as modeling and analysis tools are available.
Another commenter opined that the only pollutant that should require a
significance finding prior to the submission of a PM2.5 SIP
is ammonia.
EPA considered all of these comments along with a number of other
factors including, speciated air quality data, emissions inventory
information, and the state of the scientific understanding of the
formation of secondary particles. We based today's decision on all of
these factors as described above in section III.B.
Several commenters believed that SIP budgets for one or more of the
PM2.5 precursors should be established before conformity is
required for those precursors. Specifically, two commenters believed
that SOX and ammonia should be evaluated for significance
and have SIP budgets before conformity is required. Three other
commenters believed that conformity determinations should not be
required for any PM2.5 precursors prior to the submission of
a SIP and emissions budgets being found adequate or approved. One of
these commenters stated that Sec. Sec. 93.102(b)(2)(iii)-(v) and
93.102(b)(3) should refer to budgets because conformity should only be
required if there is an explicit motor vehicle emissions budget that is
intended to be a ceiling on future emissions.
EPA disagrees with these commenters. Clean Air Act section
176(c)(6) requires that conformity apply in new nonattainment areas one
year after the effective date of the nonattainment designation, even
prior to the submission of SIPs establishing budgets for a particular
pollutant or precursor. Clean Air Act section 176(c)(4) provides EPA
with the authority to establish conformity tests that will ensure that
transportation plans, TIPs and projects do not result in new violations
of an air quality standard, increase the frequency or severity of an
existing violation, or delay timely attainment of a standard during the
period before a SIP is submitted. While the contribution of mobile
sources to PM2.5 nonattainment problems is likely to vary
from area to area, on-road emissions of at least NOX, and
perhaps other precursors, are likely to make a significant contribution
to PM2.5 problems in most areas. Therefore, EPA believes it
is both required by the Clean Air Act and necessary to protect public
health for PM2.5 areas to begin considering the role of on-
road emissions of PM2.5 precursors in their PM2.5
air quality problems, and to demonstrate conformity for those
precursors that make a significant contribution to their air quality
problems once conformity applies for PM2.5. Before adequate
or approved SIP budgets are established, PM2.5 areas must
use one of the interim emissions tests in Sec. 93.119 to fulfill this
statutory requirement.
One commenter opined that requiring conformity for additional
precursors results in additional burden. The commenter stated that any
additional pollutant or precursor that has to be included in a
conformity determination leads to additional modeling runs, additional
documentation of results, additional explanation to the public and
regional decision makers and an additional opportunity for a conformity
lapse. This commenter believed that EPA should not minimize these
resource requirements or use this argument to support the inclusion of
PM2.5 precursors in conformity determinations prior to a SIP
submission.
EPA understands the commenter's concerns and has attempted to
structure requirements for PM2.5 precursors so that human
health and air quality are protected while targeting regional emissions
analyses to only those precursors whose on-road emissions make a
significant contribution to an area's PM2.5 air quality
problem. However, EPA continues to believe as stated in the November
2003 proposal that including PM2.5 precursors in
PM2.5 regional emissions analyses prior to the submission of
a SIP should not result in any additional transportation or emissions
modeling because PM2.5 areas will already be producing VMT
and
[[Page 24286]]
emissions estimates for direct PM2.5 (68 FR 62706). The same
VMT estimates would be used in calculating emissions of any and all
precursors. Additionally, emission factors for the relevant precursors
would generally be produced in the same model runs as the emission
factors for direct PM2.5. EPA recognizes that there would be
some small increase in burden in documenting these results and in
discussing these precursors with regional decision makers and the
public, but we believe this small increase is merited if a precursor is
a significant contributor to an area's air quality problem.
EPA also recognizes that it is possible that an area could lapse
because it may not be able to demonstrate conformity for one or more of
the PM2.5 precursors. EPA and DOT always attempt to work
with areas that are experiencing problems demonstrating conformity in
order to resolve problems before a lapse occurs. However, the Clean Air
Act's conformity requirements are intended to ensure that the use of
Federal transportation funds does not cause new air quality problems,
make existing problems worse, or delay meeting a Clean Air Act
requirement such as attainment. Therefore, if one or more precursors is
a significant contributor to an area's air quality problem, the
inability to demonstrate conformity for such precursors would be
consistent with the Clean Air Act's intended purpose of the conformity
process. In other words, if conformity cannot be demonstrated for a
significant precursor, Federal transportation funds could not be spent
on transportation activities that potentially would cause a new air
quality problem, worsen an existing problem, or delay attainment or
other emission reduction milestone. The inability to demonstrate
conformity would indicate that further action is needed before Federal
transportation funding and approvals can occur so that ultimately both
transportation and air quality goals are achieved.
2. Significance Findings
A number of commenters expressed support for significance findings
to be made by either the state air agency or the EPA regional office
before a PM2.5 SIP is submitted. However, commenters also
suggested different options for making significance findings. Thirteen
commenters stated that both the state air agency and the EPA regional
office should make the finding, while two commenters stated that the
finding should be made through an area's interagency consultation
process. Another commenter recommended that only the state should have
the ability to make significance findings.
EPA is making one change with regard to insignificance findings.
EPA has determined that insignificance findings for NOX
should be made by both the state air agency and the EPA regional
office. EPA believes that requiring both the state air agency and the
EPA regional office to make an insignificance finding for
NOX is appropriate because, as stated above in this
rulemaking, EPA has initially determined that NOX is a
significant precursor for all PM2.5 nonattainment areas.
Additionally, all other insignificance findings made within the
transportation conformity and SIP processes require both state air
agency and EPA regional office action because they are made through
either a motor vehicle emission budget adequacy finding or a SIP
approval as required by Sec. 93.109(k) of the conformity regulation.
Therefore, EPA believes that it is necessary that both the state air
agency and the EPA regional office make a finding that on-road
emissions of NOX are an insignificant contributor to an
area's PM2.5 air quality problem prior to the submission of
a SIP. A finding made by both agencies provides assurance that on-road
emissions of NOX are in fact insignificant contributors to
an area's PM2.5 air quality problem and therefore may be
omitted from conformity determinations prior to the submission of a SIP
for the area.
Finally, EPA believes that an insignificance finding for
NOX should be made by both the state air agency and the EPA
regional office because NOX is the only pollutant/precursor
for which a regional analysis is not required if a finding is made.
That is, the conformity rule allows NOX to be found
insignificant before a SIP is submitted and therefore not be included
in subsequent conformity determinations. For all other PM2.5
and PM10 pollutants/precursors covered by the conformity
rule (i.e., VOCs, SOX and ammonia as PM2.5
precursors; NOX and VOCs as PM10 precursors and
road dust as a contributor to PM2.5 air quality problems)
either the state air agency or the EPA regional office can decide if
emissions are significant and therefore should be included in
conformity determinations prior to the submission of a SIP and
emissions budgets being found adequate or approved. However, a finding
for NOX (in this case, a finding of insignificance) would
lead to a less environmentally conservative result where NOX
would no longer be considered in conformity determinations.
In contrast, consistent with the rule's requirements for
significance findings for other precursor emissions and the November 5,
2003, proposal, today's action specifies that significance findings for
VOCs, SOX and ammonia as PM2.5 precursors can be
made by either the state air agency or the EPA regional office. We
believe that changes to the procedures for finding VOCs, SOX
and ammonia precursor emissions significant in response to comments are
unnecessary because such findings would result in the inclusion of one
or more precursors in conformity which would be more environmentally
protective. Furthermore, allowing significance findings for VOCs,
SOX and ammonia to be made by either the state air agency or
the EPA regional office acknowledges the state's authority as well as
EPA's role in ensuring national consistency in such decisions. The
language used in the final rule for these three PM2.5
precursors is consistent with how such findings have been made for
PM10 precursors, since the original 1993 conformity rule.
Today's final rule for these three precursors is also consistent with
how such findings are to be made for PM2.5 road dust. The
road dust requirements were finalized in the July 1, 2004, final rule.
EPA believes that maintaining consistency in cases where precursors are
determined to be significant will facilitate implementation of the
conformity rules with no adverse impacts, in light of the role
interagency consultation will play as explained above.
One commenter, who favored including all precursors in conformity
determinations prior to the submission of a SIP, stated that a
precursor could be found to be insignificant if current on-road
emissions are less than five percent of total PM2.5 and no
increases are expected on a percentage basis during the period covered
by the SIP or the conformity determination for the area. EPA disagrees
with this suggested approach. Merely using a percentage level as a
basis for a significance or insignificance finding ignores many other
aspects of an area's nonattainment problem. Rather, EPA believes that a
combination of the criteria for insignificance findings contained in
Sec. 93.109(k) of the conformity rule and the discussion of
insignificance and significance findings as they apply to
PM2.5 precursors contained in this notice provide the
appropriate basis for deciding whether or not a PM2.5
precursor is significant or insignificant in a given area. Discussion
of EPA's rationale for establishing criteria for significance and
insignificance findings
[[Page 24287]]
can be found in the preamble to the July 1, 2004, final rule (69 FR
40061 through 40063). Therefore, EPA is not adopting the criteria
suggested by the commenter.
One commenter believed that if all precursors were considered in
conformity prior to a SIP submission it could be presumed that these
precursors will ultimately be included in the SIP for the area. In such
a case, the commenter believed it would be difficult to justify not
including the precursors in the SIP for the area if the state
presumptively includes all of them in the first conformity
determination. As previously stated, under today's final rule any
significance finding made prior to EPA's adequacy finding for budgets
in a SIP, or EPA's approval of the SIP, should not be viewed as the
ultimate determination of the significance of precursor emissions in a
given area. State and local agencies may find through the SIP
development process that emissions of one or more precursors are
significant, even if a precursor had previously been considered
insignificant. In such a case, the PM2.5 SIP would establish
a motor vehicle emissions budget for that precursor and a regional
emissions analysis for that precursor would be included in subsequent
conformity determinations. Similarly, state and local agencies may find
that a precursor is insignificant when preparing the SIP, even if
previously found significant prior to the SIP's preparation.
One commenter stated that the insignificance policy should be
applied to precursor emissions in PM2.5 nonattainment and
maintenance areas for a variety of reasons such as the need for
additional information on the nature and cause of an area's
PM2.5 problem, speciation of PM2.5 and
availability of PM2.5 control measures. EPA agrees with this
commenter. Today's final rule allows nonattainment areas to make
findings on the significance of each of the four precursors to their
PM2.5 air quality problem during the period before a SIP is
submitted and budgets are found adequate as described above. The
insignificance policy also generally applies after a SIP is submitted,
via the decisions about precursors that are determined in the SIP.
One commenter requested additional guidance on significance and
insignificance findings. EPA does not believe that additional guidance
on significance and insignificance findings is necessary at this time.
EPA has described the criteria to be considered and the process to be
used in making these findings in Sec. 93.109(k) of the conformity rule
and in today's preamble. Additional discussion and details on
insignificance findings can be found in the preamble to the July 1,
2004, final rule (69 FR 40061 through 40063).
3. Precursors in SIPs
One commenter stated that after PM2.5 SIPs are
submitted, areas should consider all four precursors in conformity
determinations unless the SIP clearly states that one or more
precursors are insignificant. EPA is not making any changes in response
to this comment. EPA does not believe that it is necessary for a SIP to
explicitly state that a precursor is insignificant. Instead, EPA
believes that states will consider the on-road contribution of all four
precursors to the PM2.5 problem as they develop their SIPs.
If through the SIP process a state concludes that on-road emissions of
one or more precursors needs to be addressed in order to attain the
PM2.5 standard as expeditiously as practicable, then EPA
expects that the state will include an emissions budget in the SIP for
each of the relevant precursors. A conformity determination will then
be required for each precursor for which there is a budget, after the
emissions budgets are found adequate or approved. In making a decision
about each precursor, states should consider the insignificance
criteria contained in Sec. 93.109(k) of the conformity rule and the
current state of the science concerning the precursor's role in the
formation of PM2.5. Once SIPs are submitted and found
adequate or approved the conformity rule requires that conformity be
assessed against the budgets in the applicable SIP. Conformity
determinations must then address all precursors for which the SIP
establishes a budget, and need not address any possible precursor for
which the state has not established a budget because the emissions of
that precursor are insignificant.
EPA notes that, if inventory and modeling analyses demonstrating
reasonable further progress, attainment or maintenance indicate a level
of emissions of a precursor that must be maintained to demonstrate
compliance with the applicable requirement, then that level of
emissions should be clearly identified in the SIP as a motor vehicle
emissions budget for transportation conformity purposes consistent with
Sec. 93.118(e) even if the SIP does not establish particular controls
for the given precursor. If the state fails to identify such a level of
emissions as a motor vehicle emissions budget, EPA will find the
submitted SIP budgets inadequate because the SIP fails to clearly
identify the motor vehicle emissions budget as required by conformity
rule Sec. 93.118(e)(4)(iii).
Several commenters raised concerns about SIP development and
regional emissions analyses in areas that are nonattainment for both 8-
hour ozone and PM2.5. One of these commenters asked if
NOX and VOC conformity analyses would be the same for both
pollutants in these areas. Another commenter asked if NOX
and VOC budgets would be the same for 8-hour ozone and PM2.5
SIPs in these areas.
EPA does not expect that either regional emissions analyses or
budgets for NOX and VOCs will be the same for 8-hour ozone
and PM2.5 standards in areas that are nonattainment for both
pollutants, for several reasons. First, it is likely that most areas
will have different attainment dates for each of the two pollutants,
which means that it is likely that analyses and budgets will be
required for different years. Second, it is possible that in many cases
the boundaries of the nonattainment area for each pollutant may be
different. For example, the 8-hour ozone nonattainment area may contain
more counties than the PM2.5 nonattainment area or vice
versa. Finally, VOC and NOX regional emissions analyses and
budgets for 8-hour ozone and PM2.5 areas will most likely be
developed using different meteorological conditions and, in some areas,
different travel patterns. For example, because in most areas, ozone is
a summertime pollutant, NOX and VOC regional emissions and
budgets in 8-hour ozone areas would be calculated using meteorological
and travel data for a ``typical'' summer day. In contrast,
NOX and VOC regional emissions and budgets for
PM2.5 areas may be established using annual averages for
meteorological and traffic conditions, rather than conditions for only
a particular season, because most PM2.5 nonattainment areas
are violating the annual PM2.5 standard instead of the 24-
hour standard.
One commenter stated that there was an error in the proposed option
1 language in Sec. 93.102(b)(iv) of the November 2003 rulemaking.
Specifically, the commenter suggested that the proposed language
appeared to require conformity determinations for NOX and
VOCs if a submitted SIP does not contain emissions budgets for
NOX and VOCs. EPA disagrees; the language as proposed for
NOX and VOCs is correct and we are retaining that language
for NOX in today's final rule. We believe that the commenter
misunderstood the proposal. The language in Sec. 93.102(b)(iv) that is
finalized today requires that conformity
[[Page 24288]]
determinations be made for NOX unless: (1) During the period
before a SIP is submitted and budgets are found adequate or approved
the state air agency and EPA regional office make a finding that on-
road emissions of NOX are not significant contributors to an
area's air quality problem; and/or (2) the area's SIP does not
establish an emissions budget for on-road emissions of NOX.
In other words, if the SIP includes an adequate or approved emissions
budget for NOX, then NOX must be analyzed in
conformity determinations in PM2.5 nonattainment areas. In
contrast, if the SIP does not contain a budget for NOX and
instead concludes that emissions of NOX could rise to any
reasonably foreseeable level without impairing reasonable further
progress or attainment, EPA would make an insignificance finding,
either through a motor vehicle emissions budget adequacy finding or
through a SIP approval, and NOX would not have to be
considered for conformity purposes.
4. Modeling Concerns
Several commenters expressed concerns about generating estimates
for PM2.5 precursors. One commenter stated that few areas
have experience using MOBILE6 to evaluate PM2.5 emissions
and that unexpected issues and problems will arise from the use of
MOBILE6. The commenter believed that difficulties will come from both
model shortcomings and inexperience of the users. Another commenter had
concerns about relying on a future release of MOBILE6.2 or other future
guidance for estimating precursor emissions. A third commenter stated
that there is a need for guidance on analysis techniques for ammonia
and SOX.
Since the conformity proposal was published in November 2003, EPA
has released MOBILE6.2. MOBILE6.2 is based on the latest available
information concerning vehicle emissions and is therefore the best
available tool at this time for calculating on-road emissions of
PM2.5 precursors (in all states except California). The
Federal Register notice announcing the release of the model was
published on May 19, 2004 (69 FR 28830). EPA released SIP and
conformity policy guidance on the use of MOBILE6.2 on February 24,
2004, entitled, ``Policy Guidance on the Use of MOBILE6.2 and the
December 2003 AP-42 Method for Re-Entrained Road Dust for SIP
Development and Transportation Conformity.'' EPA released technical
guidance on the use of the MOBILE6.2 model in August 2004. Information
on training in the use of MOBILE6.2, related policy memoranda and the
technical guidance in the use of the model are available on EPA's
MOBILE Web site at http://www.epa.gov/otaq/m6.htm.
EPA understands the concerns that these commenters have expressed
about estimating precursors. However, we believe there is adequate time
for new areas to gain MOBILE experience and conduct conformity analyses
for the PM2.5 standard before the end of the one-year
conformity grace period. We believe that the material described above
contains sufficient information for the states that use MOBILE to
conduct modeling of on-road emissions of ammonia and SOX.
Therefore, we believe that additional guidance or analytical techniques
for estimating these precursors is unnecessary. EPA recognizes,
however, that California needs to complete the development of a
methodology for estimating on-road emissions of ammonia before ammonia
would be included in conformity determinations in California, as
discussed above in Section III. A.
5. State of the Science
Two commenters expressed concern about the current understanding of
the formation of secondary particles. One commenter stated that the
role of ammonia needs to be evaluated quickly so that states can have
all information possible while they plan to attain the PM2.5
standard. The other commenter stated that there is a lack of
understanding about the formation of secondary particles. This
commenter believed that unnecessary analysis of potential
PM2.5 precursors would be time consuming and overly
burdensome without producing substantial air quality benefits.
EPA acknowledges that our understanding of the formation of
secondary particles is not complete. However, EPA believes that this
final rule strikes an appropriate balance between preserving limited
state and local resources and environmental protection. Our incomplete
understanding of the role of VOCs and ammonia in the formation of
secondary particles is one of the reasons that we determined that
PM2.5 nonattainment areas should not be required to address
those precursors in conformity determinations before SIP budgets are
available unless a significance finding is made. On the other hand, EPA
believes that there is clear evidence and a substantial understanding
of the role of NOX and SOX in the formation of
secondary particles. Additional information on the role of each of the
precursors can be found in the U.S. EPA Criteria Document,\6\ and in
the NARSTO Fine Particle Assessment.\7\
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\6\ USEPA, 2003. Air Quality Criteria for Particulate Matter
(Fourth External Review Draft). EPA/600/P-99/002aD and bD. U.S.
Environmental Protection Agency, Office of Research and Development,
National Center For Environmental Assessment, Research Triangle Park
Office, Research Triangle Park, NC. June 2003. Available
electronically at http://cfpub.epa.gov/ncea/cfm/partmatt.cfm.
\7\ North American Research Strategy for Tropospheric Ozone
(NARSTO) and Particulate Matter, Particulate Matter Science for
Policy Makers--A NARSTO Assessment, Parts 1 and 2. NARSTO Management
Office (Envair), Pasco, Washington. February 2003.
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EPA agrees that further research is needed on the role of ammonia
in particle formation and the benefits of ammonia control measures.
Ongoing research is expected to greatly improve our understanding of
ammonia control measures as well as our understanding of the role of
ammonia in aerosol formation. However, as states and EPA develop a
greater understanding over the coming years about the air quality
effects of reducing ammonia emissions in specific nonattainment areas,
it may be appropriate for ammonia reduction strategies to be included
in future SIPs and it may be appropriate to include ammonia in future
conformity determinations.
6. Comment Period
One commenter requested an additional comment period for
PM2.5 related requirements. As stated in the July 1, 2004,
Federal Register notice, EPA determined that it is not necessary to
reopen the comment period on the proposed options for addressing
PM2.5 precursors in conformity determinations (69 FR 40032).
EPA published a supplemental proposal on PM2.5 hot-spot
analyses on December 13, 2004. Providing the public with an opportunity
to comment the proposed options for hot-spot analyses. Additionally,
when EPA publishes the proposed PM2.5 implementation
strategy the public will have the opportunity to comment on that
proposal as well. EPA concludes that the comment periods for these
rulemakings has provided the public with adequate time to comment on
additional issues related to PM2.5.
IV. Technical Correction to Public Consultation Procedures
In this action, we are correcting a cross-reference to a provision
of DOT's transportation planning regulations that is cited under the
public consultation procedure requirements in Sec. 93.105(e) of the
conformity rule. This cross-reference to the transportation planning
regulations is intended to specify the provision of DOT's regulations
that
[[Page 24289]]
contains the fee schedule for public inspection and copying of
transportation planning and conformity documents. Prior to today's
action the cross-reference was listed as 49 CFR 7.95; this final rule
changes the cross-reference to 49 CFR 7.43.
EPA is making this technical correction to Sec. 93.105(e) as a
result of DOT's July 16, 1998, final rule that changed the citation of
the transportation planning fee schedule provision (63 FR 38331). We
did not issue a proposal or provide an opportunity for public comment
for this minor correction to the rule. We believe such actions are
unnecessary because this minor revision in no way changes the
substantive public consultation procedures described in Sec. 93.105(e)
of the conformity rule. This revision merely updates a cross reference
in the conformity rule to be consistent with the recodification of
DOT's regulations so that implementers can more easily locate the
correct corresponding DOT regulation.
V. How Does Today's Final Rule Affect Conformity SIPs?
Today's final rule does not affect conformity SIP requirements. In
all nonattainment and maintenance areas with and without approved
conformity SIPs, the final rule requirements for PM2.5
precursors will apply immediately upon the effective date of today's
action because no prior conformity rules (or approved conformity SIPs)
address precursors for PM2.5. The technical correction to
Sec. 93.105(e) included in this rulemaking will apply immediately upon
the effective date in all areas except those that have an approved
conformity SIP containing this provision. For these areas, the Sec.
93.105(e) correction will not be reflected in their SIPs until the
state includes the correction in a SIP revision and EPA approves that
revision. EPA has no authority to disregard this statutory requirement
for this portion of today's final rule. EPA does not believe, however,
that the conformity SIP requirement will preclude areas with approved
SIPs from appropriately implementing Sec. 93.105(e), as today's action
merely corrects a cross-reference to DOT's transportation planning
regulations. We believe that areas can interpret their approved
conformity SIPs consistent with today's change to reflect the new
correct citation. We believe this interpretation would be reasonable,
given that this change to DOT's fee schedule rules is merely one of
reorganizing and not one of substance. EPA will work with states as
appropriate to approve revisions to their conformity SIPs as
expeditiously as possible through flexible administrative techniques
such as parallel processing and direct final rulemaking. EPA released
guidance on conformity SIPs on November 18, 2004, entitled,
``Conformity SIP Guidance.'' This guidance is primarily intended to
assist areas with approved conformity SIPs determine which provisions
of the July 1, 2004, conformity rule amendments apply immediately and
which provisions cannot apply until their conformity SIPs are revised.
By way of background, Clean Air Act section 176(c)(4)(C) currently
requires states to submit revisions to their SIPs to reflect the
criteria and procedures for determining conformity. States can choose
to develop conformity SIPs as a memorandum of understanding (MOU),
memorandum of agreement (MOA), or state rule. However, a state must
have and use its authority to make an MOU or MOA enforceable as a
matter of state law, if such mechanisms are used. Section 51.390(b) of
the conformity rule specifies that after EPA approves a conformity SIP
revision, the federal conformity rule no longer governs conformity
determinations (for the parts of the rule that are covered by the
approved conformity SIP). In accordance with Sec. 51.390, states must
submit a revision to their conformity SIP to reflect the provisions of
this final rule within 12 months of the publication date.
VI. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
Under Executive Order 12866, (58 FR 51735; October 4, 1993) the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The Order defines ``significant regulatory action'' as
one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more,
or otherwise adversely affect in a material way the economy; a sector
of the economy; productivity; competition; jobs; the environment;
public health or safety; or State, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof;
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
It has been determined that this final rule is not a ``significant
regulatory action'' under the terms of Executive Order and therefore
not subject to OMB.
B. Paperwork Reduction Act
The Office of Management and Budget (OMB) has approved the
information collection requirements contained in this rule under the
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. And
has assigned OMB control number 2060-0561.
Transportation conformity determinations are required under Clean
Air Act section 176(c) (42 U.S.C. 7506(c)) to ensure that federally
supported highway and transit project activities are consistent with
(``conform to'') the purpose of the SIP. Conformity to the purpose of
the SIP means that transportation activities will not cause or
contribute to new air quality violations, worsen existing violations,
or delay timely attainment of the relevant air quality standards.
Transportation conformity applies under EPA's conformity regulations at
40 CFR parts 51.390 and 93 to areas that are designated nonattainment
and those redesignated to attainment after 1990 (``maintenance areas''
with SIPs developed under Clean Air Act section 175A) for
transportation-source criteria pollutants. The Clean Air Act gives EPA
the statutory authority to establish the criteria and procedures for
determining whether transportation activities conform to the SIP.
EPA provided two opportunities for public comment on the
incremental burden estimates for transportation conformity
determinations under the new 8-hour ozone and PM2.5
standards. EPA received comments on both the initial burden estimates
provided in the November 5, 2003, proposal (68 FR 62720) and on the
revised estimates in the January 5, 2004, ICR (69 FR 336). EPA
responded to all of these comments in the ICR that has been approved by
OMB. This ICR addresses all aspects of the conformity rulemaking effort
for the new air quality standards. EPA estimated burden in this ICR is
based on implementing the most intensive options proposed for all
aspects of the conformity rules, including PM2.5 precursors.
The options selected in today's final action are consistent with the
burden estimated in the ICR.
Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a federal
[[Page 24290]]
agency. This includes the time needed to review instructions; develop,
acquire, install and utilize technology and systems for the purposes of
collecting, validating, and verifying information; process and maintain
information; and disclose and provide information; adjust the existing
ways to comply with any previously applicable instructions and
requirements; train personnel to be able to respond to a collection of
information; search data sources; complete and review the collection of
information; and, transmit or otherwise disclose the information.
An agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9. In addition, EPA has
amended the table in 40 CFR part 9 of currently approved OMB control
numbers for various regulations to list the regulatory citations for
the information requirements contained in this final rule.
C. Regulatory Flexibility Act
The Regulatory Flexibility Act, as amended by the Small Business
Regulatory Enforcement Fairness Act of 1996, requires the Agency to
prepare a regulatory flexibility analysis of any rule subject to notice
and comment rulemaking requirements under the Administrative Procedure
Act or any other statute unless the agency certifies that the rule will
not have a significant economic impact on a substantial number of small
entities. Small entities include small businesses, small not-for-profit
organizations and small governmental jurisdictions.
For purposes of assessing the impacts of today's final rule on
small entities, small entity is defined as: (1) A small business as
defined by the Small Business Administration's (SBA) regulations at 13
CFR 121.201; (2) a small governmental jurisdiction that is a government
of a city, county, town, school district or special district with a
population of less than 50,000; and (3) a small organization that is
any not-for-profit enterprise 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, state departments of
transportation and metropolitan planning organizations that, by
definition, are designated under Federal transportation laws only for
metropolitan areas with a population of at least 50,000. These
organizations do not constitute small entities within the meaning of
the Regulatory Flexibility Act.
D. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``federal mandates'' that
may result in expenditures to State, local, and tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
EPA has determined that this final rule itself does not contain a
Federal mandate that may result in expenditures of $100 million or more
for State, local, and tribal governments, in the aggregate, or the
private sector in any one year. The primary purpose of this rulemaking
is to incorporate into the conformity regulations the PM2.5
precursors that must be considered in conformity determinations in
PM2.5 nonattainment and maintenance areas. Clean Air Act
section 176(c)(5) requires the applicability of conformity to such
areas as a matter of law one year after nonattainment designations.
Therefore, 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. As a result, today's action is not subject to the
requirements of sections 202 and 205 of the UMRA and EPA has not
prepared a statement with respect to budgetary impacts.
E. Executive Order 13132: Federalism
Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by state and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the states, on the relationship between the national
government and the states, or on the distribution of power and
responsibilities among the various levels of government.''
This final rule does not have federalism implications. It will not
have substantial direct effects on the states, on the relationship
between the National Government and the States, or on the distribution
of power and responsibilities among the various levels of government,
as specified in Executive Order 13132. The Clean Air Act requires
conformity to apply in certain nonattainment and maintenance areas as a
matter of law, and this final rule merely establishes and revises
procedures for transportation planning entities in subject areas to
follow in meeting their existing statutory obligations. Thus, Executive
Order 13132 does not apply to this rule.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
Executive Order 13175: ``Consultation and Coordination with Indian
Tribal Governments'' (65 FR 67249, November 6, 2000), requires EPA to
develop an accountable process to ensure ``meaningful and timely input
by tribal officials in the development of regulatory policies that have
tribal implications.'' ``Policies that have tribal implications'' is
defined in the Executive Order to include regulations that have
``substantial direct effects on one or more Indian tribes, on the
relationship between the Federal Government and the Indian tribes, or
on
[[Page 24291]]
the distribution of power and responsibilities between the Federal
Government and Indian tribes.''
Today's amendments to the conformity rule do not significantly or
uniquely affect the communities of Indian tribal governments, as the
Clean Air Act already requires transportation conformity to apply as a
matter of law in any area that is designated nonattainment or
maintenance. This final rule incorporates into the conformity rule
provisions addressing newly designated PM2.5 nonattainment
and maintenance areas subject to conformity requirements as a matter of
law under the Act that would not themselves have substantial direct
effects on tribal governments, on the relationship between the Federal
Government and Indian tribes, or on the distribution of power and
responsibilities between the Federal Government and Indian tribes, as
specified in Executive Order 13175. Accordingly, the requirements of
Executive Order 13175 are not applicable to this final rule.
G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks
Executive Order 13045: ``Protection of Children from Environmental
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997), applies
to any rule that: (1) Is determined to be ``economically significant''
as defined under Executive Order 12866, and (2) concerns an
environmental health or safety risk that EPA has reason to believe may
have a disproportionate effect on children. If the regulatory action
meets both criteria, the Agency must evaluate the environmental health
or safety effects of the planned rule on children, and explain why the
planned regulation is preferable to other potentially effective and
reasonably feasible alternatives considered by the Agency.
This final rule is not subject to Executive Order 13045 because it
is not economically significant within the meaning of Executive Order
12866 and does not involve the consideration of relative environmental
health or safety risks on children.
H. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution or Use
This final rule is not subject to Executive Order 13211, ``Action
Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use'' (66 FR 28355; May 22, 2001), because it will not
have a significant adverse effect on the supply, distribution, or use
of energy.
I. National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113, section 12(d) (15 U.S.C.
272 note) directs EPA to use voluntary consensus standards in its
regulatory activities unless to do so would be inconsistent with
applicable law or otherwise impractical. ``Voluntary consensus
standards'' are technical standards (e.g., materials specifications,
test methods, sampling procedures, and business practices) that are
developed or adopted by voluntary consensus standards bodies. The NTTAA
directs EPA to provide Congress, through OMB, explanations when the
Agency decides not to use available and applicable voluntary consensus
standards.
This rulemaking does not involve technical standards. Therefore,
the use of voluntary consensus standards does not apply to this final
rule.
J. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. The EPA will submit this final rule and other required
information to the U.S. Senate, the U.S. House of Representatives, and
the Comptroller General of the United States prior to publication of
the final rule in the Federal Register. This rule is not a ``major
rule'' as defined by 5 U.S.C. 804(2). This rule will be effective on
June 6, 2005.
K. Petitions for Judicial Review
Under section 307(b)(1) of the Clean Air Act, petitions for
judicial review of this action must be filed in the United States Court
of Appeals for the appropriate circuit by July 5, 2005. Filing a
petition for reconsideration by the Administrator of this final rule
does not affect the finality of this rule for the purposes of judicial
review, nor does it extend the time within which a petition for
judicial review may be filed, and shall not postpone the effectiveness
of such a rule or action. This action may not be challenged later in
proceeding to enforce its requirements. (See section 307(b)(2) of the
Administrative Procedures Act.)
List of Subjects in 40 CFR Part 93
Environmental protection, Administrative practice and procedure,
Air pollution control, Intergovernmental relations, Nitrogen dioxide,
Particulate matter, Transportation, Volatile organic compounds.
Dated: May 2, 2005.
Stephen L. Johnson,
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 93.102 is amended by:
0
a. removing the word ``and'' at the end of paragraph (b)(2)(ii);
0
b. removing the period at the end of paragraph (b)(2)(iii) and
replacing it with a semicolon; and
0
c. adding paragraphs (b)(2)(iv) and (v).
The revisions and additions read as follows:
Sec. 93.102 Applicability.
* * * * *
(b) * * *
(2) * * *
(iv) NOX in PM2.5 areas, unless both the EPA
Regional Administrator and the director of the state air agency have
made a finding that transportation-related emissions of NOX
within the nonattainment area are not a significant contributor to the
PM2.5 nonattainment problem and has so notified the MPO and
DOT, or the applicable implementation plan (or implementation plan
submission) does not establish an approved (or adequate) budget for
such emissions as part of the reasonable further progress, attainment
or maintenance strategy; and
(v) VOC, sulfur oxides (SOX) and/or ammonia (NH3) in
PM2.5 areas either if the EPA Regional Administrator or the
director of the state air agency has made a finding that
transportation-related emissions of any of these precursors within the
nonattainment area are a significant contributor to the
PM2.5 nonattainment problem and has so notified the MPO and
DOT, or if the applicable implementation plan (or implementation plan
submission) establishes an approved (or adequate) budget for such
emissions as part of the reasonable further progress, attainment or
maintenance strategy.
* * * * *
0
3. Section 93.105(e) is amended by revising the reference ``49 CFR
7.95'' to read ``49 CFR 7.43.''
0
4. Section 93.119 is amended by:
0
a. removing the word ``and'' at the end of paragraph (f)(7);
[[Page 24292]]
0
b. removing the period at the end of paragraph (f)(8) and replacing it
with a semicolon; and
0
c. adding new paragraphs (f)(9) and (f)(10).
The revisions and additions read as follows:
Sec. 93.119 Criteria and procedures: Interim emissions in areas
without motor vehicle emissions budgets.
* * * * *
(f) * * *
(9) NOX in PM2.5 areas, unless the EPA
Regional Administrator and the director of the State air agency have
made a finding that emissions of NOX from within the area
are not a significant contributor to the PM2.5 nonattainment
problem and has so notified the MPO and DOT; and
(10) VOC, SOX and/or ammonia in PM2.5 areas
if the EPA Regional Administrator or the director of the State air
agency has made a finding that any of such precursor emissions from
within the area are a significant contributor to the PM2.5
nonattainment problem and has so notified the MPO and DOT.
* * * * *
[FR Doc. 05-9086 Filed 5-5-05; 8:45 am]
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