or the PM2.5 NAAQS. If these existing controls are not
sufficient for an area to reach attainment with the NO2
NAAQS, EPA would expect the State to implement additional control
measures that would bring the area into attainment by the deadline. For
a designation based on data from a near roadway monitor EPA would
expect the States to give primary consideration to controlling
emissions from on-road sources; however, it is likely that other types
of sources contribute to the concentrations that are measured at a near
roadway monitor and a State may decide to implement controls on these
other contributing sources.
    The Clean Air Act requires that EPA finalize designations within
two years after a NAAQS is revised unless the available air quality
data is insufficient to make designations by that time. In that case,
EPA must finalize designations within three years after the NAAQS is
revised. As discussed elsewhere in today's final rule, EPA believes
that it has sufficient data to make designations within two years and
that most areas will be designated as unclassifiable at that time.
Taking the additional year provided by the CAA would not allow
additional data from the new near roadway monitors to be factored into
the designations process in any event. Therefore, it is EPA's intention
to designate areas within two years as required by the Act. EPA intends
to redesignate areas once it has sufficient data from the new
monitoring network to designate areas as clearly attaining or not
attaining the standard.
c. Final
    The EPA is not making any changes to the discussion on
nonattainment area SIPs in the proposed rule.
2. New Source Review and Prevention of Significant Deterioration
Requirements
a. Proposal
    The Prevention of Significant Deterioration (PSD) and nonattainment
New Source Review (NSR) programs contained in parts C and D of Title I
of the CAA govern preconstruction review of any new or modified major
stationary sources of air pollutants regulated under the CAA as well as
any precursors to the formation of that pollutant when identified for
regulation by the Administrator.\28\ The EPA rules addressing these
programs can be found at 40 CFR 51.165, 51.166, 52.21, 52.24, and part
51, appendix S. States which have areas designated as nonattainment for
the NO2 NAAQS must submit, as a part of the SIP due 18
months after an area is designated as nonattainment, provisions
requiring permits for the construction and operation of new or modified
stationary sources anywhere in the nonattainment area. SIPs that
address the PSD requirements related to attainment areas are due no
later than 3 years after the promulgation of a revised NAAQS for
NO2.
---------------------------------------------------------------------------

    \28\ The terms ``major'' and ``minor'' define the size of a
stationary source, for applicability purposes, in terms of an annual
emissions rate (tons per year, tpy) for a pollutant. Generally, a
minor source is any source that is not ``major.'' ``Major'' is
defined by the applicable regulations--PSD or nonattainment NSR.
---------------------------------------------------------------------------

    The NSR program is composed of three different permit programs:
     Prevention of Significant Deterioration (PSD).
     Nonattainment NSR (NA NSR).
     Minor NSR.
    The PSD program applies when a major source, that is located in an
area that is designated as attainment or

unclassifiable for any criteria pollutant, is constructed, or undergoes
a major modification.\29\ The nonattainment NSR program applies on a
pollutant-specific basis when a major source constructs or modifies in
an area that is designated as nonattainment for that pollutant. The
minor source NSR program addresses both major and minor sources which
undergo construction or modification activities that do not qualify as
major, and it applies, as necessary to assure attainment, regardless of
the designation of the area in which a source is located.
---------------------------------------------------------------------------

    \29\ In addition, the PSD program applies to non-criteria
pollutants subject to regulation under the Act, except those
pollutants regulated under section 112 and pollutants subject to
regulation only under section 211(o).
---------------------------------------------------------------------------

    The PSD requirements include but are not limited to the following:
     Installation of Best Available Control Technology (BACT);
     Air quality monitoring and modeling analyses to ensure
that a project's emissions will not cause or contribute to a violation
of any NAAQS or maximum allowable pollutant increase (PSD increment);
     Notification of Federal Land Manager of nearby Class I
areas; and
     Public comment on permit.
    Nonattainment NSR requirements include but are not limited to:
     Installation of Lowest Achievable Emissions Rate (LAER)
control technology;
     Offsetting new emissions with creditable emissions
reductions;
     A certification that all major sources owned and operated
in the State by the same owner are in compliance with all applicable
requirements under the CAA;
     An alternative siting analysis demonstrating that the
benefits of a proposed source significantly outweigh the environmental
and social costs imposed as a result of its location, construction, or
modification; and
     Public comment on the permit.
    Minor NSR programs must meet the statutory requirements in section
110(a)(2)(C) of the CAA which requires ``* * * regulation of the
modification and construction of any stationary source * * * as
necessary to assure that the [NAAQS] are achieved.'' Areas which are
newly designated as nonattainment for the NO2 NAAQS as a
result of any changes made to the NAAQS will be required to adopt a
nonattainment NSR program to address major sources of NO2
where the program does not currently exist for the NO2 NAAQS
and may need to amend their minor source program as well. Prior to
adoption of the SIP revision addressing major source nonattainment NSR
for NO2 nonattainment areas, the requirements of 40 CFR part
51, appendix S may apply.
b. Public Comments
    One commenter claimed that EPA's setting of a more stringent
standard, i.e., short-term NO2 NAAQS, could have important
implications for NSR and PSD and title V permits. Another commenter
indicated that the promulgation of a new 1-hr NO2 short-term
standard could create the need for a short-term PSD increment. Another
commenter stated that a 1-hr NO2 Significant Impact Level
(SIL) should be developed.
    The EPA acknowledges that a decision to promulgate a new short-term
NO2 NAAQS will clearly have implications for the air
permitting process. The full extent of how a new short-term
NO2 NAAAQS will affect the NSR process will need to be
carefully evaluated. First, major new and modified sources applying for
NSR/PSD permits will initially be required to demonstrate that their
proposed emissions increases of NOX will not cause or
contribute to a violation of either the annual or 1-hour NO2
NAAQS and the annual PSD increment. In addition, we believe that
section 166 of the CAA authorizes us to consider the need to promulgate
a new 1-hour increment. Historically, EPA has developed increments for
each applicable averaging period for which a NAAQS has been
promulgated. However, increments for a particular pollutant do not
necessarily need to match the averaging periods that have been
established for NAAQS for the same pollutant. Environmental Defense
Fund, Inc. v. EPA, 898 F.2d 183, 189-190 (DC Cir. 1990) (`` * * * the
`goals and purposes' of the PSD program, set forth in 160, are not
identical to the criteria on which the ambient standards are based.'')
Thus, we would need to evaluate the need for a new 1-hour
NO2 increment in association with the goals and purposes of
the statutory PSD program requirements.
    We also believe that there may be a need to revise the screening
tools currently used under the NSR/PSD program for completing
NO2 analyses. These screening tools include the significant
impact levels (SILs), as mentioned by one commenter, but also include
the significant emissions rate for emissions of NOX and the
significant monitoring concentration (SMC) for NO2. EPA
intends to evaluate the need for possible changes or additions to each
of these important screening tools for NOX/NO2
due to the addition of a 1-hour NO2 NAAQS. If changes or
additions are deemed necessary, EPA will propose any such changes for
public notice and comment in a separate action.
c. Final
    The EPA is not making any changes to the discussion concerning the
requirements for NSR and PSD as stated in the proposed rule.
3. General Conformity
a. Proposal
    Section 176(c) of the CAA, as amended (42 U.S.C. 7401 et seq.),
requires that all Federal actions conform to an applicable
implementation plan developed pursuant to section 110 and part D of the
CAA. The EPA rules, developed under the authority of section 176(c) of
the CAA, prescribe the criteria and procedures for demonstrating and
assuring conformity of Federal actions to a SIP. Each Federal agency
must determine that any actions covered by the general conformity rule
conform to the applicable SIP before the action is taken. The criteria
and procedures for conformity apply only in nonattainment areas and
those areas redesignated attainment since 1990 (``maintenance areas'')
with respect to the criteria pollutants under the CAA: \30\ carbon
monoxide (CO), lead (Pb), nitrogen dioxide (NO2), ozone
(O3), particulate matter (PM2.5 and
PM10), and sulfur dioxide (SO2). The general
conformity rules apply one year following the effective date of
designations for any new or revised NAAQS.
---------------------------------------------------------------------------

    \30\ Criteria pollutants are those pollutants for which EPA has
established a NAAQS under section 109 of the CAA.
---------------------------------------------------------------------------

    The general conformity determination examines the impacts of direct
and indirect emissions related to Federal actions. The general
conformity rule provides several options to satisfy air quality
criteria, such as modeling or offsets, and requires the Federal action
to also meet any applicable SIP requirements and emissions milestones.
The general conformity rule also requires that notices of draft and
final general conformity determinations be provided directly to air
quality regulatory agencies and to the public by publication in a local
newspaper.
b. Final
    EPA did not receive any comments on this aspect of the proposed
rule and is not making any changes to the discussion concerning general
conformity stated in the proposed rule.

4. Transportation Conformity
a. Proposal
    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
projects will not cause new air quality violations, worsen existing
violations, or delay timely attainment of the relevant NAAQS or interim
reductions and milestones. Transportation conformity applies to areas
that are designated nonattainment and maintenance for transportation-
related criteria pollutants: Carbon monoxide (CO), ozone
(O3), nitrogen dioxide (NO2), and particulate
matter (PM2.5 and PM10). Transportation
conformity for a revised NO2 NAAQS does not apply until one
year after the effective date of a nonattainment designation. (See CAA
section 176(c)(6) and 40 CFR 93.102(d)).
    EPA's Transportation Conformity Rule (40 CFR 51.390, and Part 93,
Subpart A establishes the criteria and procedures for determining
whether transportation activities conform to the SIP. The EPA is not
making changes to the Transportation Conformity rule in this
rulemaking. However, in the future, EPA will review the need to conduct
a rulemaking to establish any new or revised transportation conformity
tests that would apply under a revision to the NO2 NAAQS for
transportation plans, TIPs, and applicable highway and transit
projects.
b. Public Comments
    Several commenters stated that transportation conformity could stop
the funding of highway and transit projects in NO2
nonattainment areas. These commenters stated that if an area fails to
demonstrate conformity, it enters a conformity lapse and only certain
types of projects can be funded during a lapse. The commenters further
stated that the NO2 NAAQS will require more areas to
determine conformity for the first time. The commenters also expressed
concern that the NO2 NAAQS proposal did not contain
sufficient information to understand to what extent revisions to the
NAAQS, and the NO2 monitoring requirements, will result in
transportation conformity requirements for individual transportation
projects such as the need for a hot-spot analysis. The commenters
further stated that hot-spot analyses could result in needless delays
for transportation improvement projects.
    With regard to the comment that more areas will have to demonstrate
conformity for the first time due to the revisions to the
NO2 NAAQS, given that today's final rule is requiring that
near roadway monitoring be carried out in urban areas with populations
greater than 350K, EPA believes that most areas with such populations
that would be designated nonattainment for NO2 are already
designated nonattainment or maintenance for one or more of the other
transportation-related criteria pollutants (ozone, PM2.5,
PM10 and carbon monoxide). As such, these areas would have
experience in making transportation conformity determinations. If areas
with no conformity experience are designated nonattainment for the
NO2 NAAQS, EPA and U.S. DOT would be available to assist
areas in implementing the transportation conformity requirements.
    The commenter expressed concern that transportation conformity
could stop highway and transit funding because areas could experience a
conformity lapse and in such cases only certain types of projects could
be funded. A conformity lapse occurs when an area misses a deadline for
a required conformity determination. A new nonattainment area must
demonstrate conformity within one year after the effective date of its
designation. For any areas designated nonattainment for the revised
NO2 NAAQS in early-2012, they would have to determine
conformity within one year of the effective date of that designation
which would be in early-2013. If that date was missed, a lapse would
occur and only projects exempt from conformity such as safety projects,
transportation control measures in an approved SIP for the area and
projects or project phases that were approved by U.S. DOT before the
lapse began can proceed during the lapse. EPA's experience in
implementing the 1997 ozone and PM2.5 NAAQS shows that
nearly all areas make their initial conformity determinations within
the one-year grace period. Areas can also lapse if they fail to
determine conformity by an applicable deadline such as determining
conformity within two years after motor vehicle emissions budgets are
found adequate. However, areas that miss one of these conformity
deadlines have a one-year grace period before the lapse goes into
effect. During the grace period, the area can continue to advance
projects from the transportation plan and transportation improvement
program. EPA's experience is that areas generally are able to make a
conformity determination before the end of the grace period.
    The commenter expressed concern that the NO2 NAAQS
proposal did not contain sufficient detail concerning possible project-
level requirements for transportation projects and that any
requirements for hot-spot analyses could needlessly delay
transportation projects. As EPA indicated in the NPRM, EPA is
considering whether to revise the transportation conformity rule to
establish requirements that would apply to transportation plans,
transportation improvement programs and/or transportation projects in
NO2 nonattainment and maintenance areas. If EPA concludes
that the conformity rule must be revised in light of the final
NO2 NAAQS, we will conduct notice and comment rulemaking to
accomplish the revisions. At that time interested parties will have the
opportunity to comment on any transportation conformity NPRM. This is
the same course of action that EPA has taken with respect to revising
the transportation conformity rule for the ozone and PM2.5
NAAQS.
    With regard to the commenter's assertion that a requirement for
hot-spot analyses for individual projects would needlessly delay
transportation projects, EPA disagrees. First, CAA section 176(c)(1)(B)
requires that transportation projects not cause new violations or make
existing violations worse, or delay timely attainment or cause an
interim milestone to be missed. EPA would only impose a hot-spot
requirement for projects in NO2 nonattainment and
maintenance areas if they are necessary to comply with CAA conformity
requirements and therefore are needed to protect public health by
reducing exposures to unhealthy levels of NO2 that could be
created by the implementation of a proposed highway or transit project.
The public would be exposed to unhealthy levels of NO2 if a
highway or transit project caused a new violation of the NO2
NAAQS, made an existing violation worse, or delayed timely attainment
or delayed achieving an interim emissions milestone. If any delay in
the project did occur, it would not be viewed as needless as it
occurred for the important purpose of protecting the exposed public's
health. Second, EPA does not agree that requiring a hot-spot analysis
would needlessly delay projects in NO2 nonattainment areas.
Such hot-spot analyses, if they are eventually required, generally
would be done as part of the NEPA process, which these projects are
already subject to; therefore, conducting an NO2 hot-spot
analysis would not be introducing a new step to a project's approval
process, but rather would add one additional analysis which must be
completed as part of an existing project approval process.

c. Final
    EPA is not making any changes to the discussion concerning
transportation conformity as stated in the proposed rule.

VII. Communication of Public Health Information

    Information on the public health implications of ambient
concentrations of criteria pollutants is currently made available
primarily through EPA's Air Quality Index (AQI) program. This section
describes the conforming changes that were proposed, major comments
received on these changes, EPA's responses to these comments and final
decisions on the AQI breakpoints. Recognizing the importance of
revising the AQI in a timely manner to be consistent with any revisions
to the NAAQS, EPA proposed conforming changes to the AQI in connection
with the final decision on the NO2 NAAQS if revisions to the
primary standard were promulgated. Conforming changes would include
setting the 100 level of the AQI at the same level as the revised
primary NO2 NAAQS and also setting the other AQI breakpoints
at the lower end of the AQI scale (i.e., AQI values of 50 and 150). EPA
did not propose to change breakpoints at the higher end of the AQI
scale (from 200 to 500), which would apply to State contingency plans
or the Significant Harm Level (40 CFR 51.16), because the information
from this review does not inform decisions about breakpoints at those
higher levels.
    With regard to an AQI value of 50, the breakpoint between the good
and moderate categories, EPA proposed to set this value to be between
0.040 and 0.053 ppm NO2, 1-hour average. EPA proposed that
the figure towards the lower end of this range would be appropriate if
the standard is set towards the lower end of the proposed range for the
standard (e.g. 80 ppb), while figures towards the higher end of the
range would be more appropriate for standards set at the higher end of
the range for the standard (e.g., 100 ppb). EPA noted that historically
this value is set at the level of the annual NAAQS, if there is one, or
one-half the level of the short-term NAAQS in the absence of an annual
NAAQS, and solicited comments on this range for an AQI of 50 and the
appropriate basis for selecting an AQI of 50 within this range.
    With regard to an AQI value of 150, the breakpoint between the
unhealthy for sensitive groups and unhealthy categories, the range of
0.360 to 0.370 ppm NO2, 1-hour average, represents the
midpoint between the proposed range for the short-term standard and the
level of an AQI value of 200 (0.64 ppm NO2, 1-hour average).
Therefore, EPA proposed to set the AQI value of 150 to be between 0.360
and 0.370 ppm NO2, 1-hour average.
    EPA received comments from several State environmental agencies and
organizations of State and local agencies that generally expressed the
view that the AQI was designed to provide the public with information
about regional air quality and therefore it should be based on
community-wide monitors. These commenters went on to state that using
near-road NO2 monitors for the AQI would present problems
because they would not represent regional NO2 concentrations
and it would be difficult to communicate this type of information to
the public using the AQI. Some expressed concern that NO2
measured at near-roadway monitors could be the critical pollutant and
could drive the AQI even though it may not represent air quality across
the area. Other agencies expressed concern that there is currently no
way to forecast ambient NO2 levels near roadways. One State
agency commented that the AQI is intended to represent air quality
where people live, work and play.
    EPA agrees with commenters that the AQI should represent regional
air quality, and that measurements that apply to a limited area should
not be used to characterize air quality across the region. Community-
wide NO2 monitors should be used to characterize air quality
across the region. However, the AQI reporting requirements encourage,
but do not require, the reporting of index values of sub-areas of an
MSA. We agree with the commenter that stated the view that the AQI is
intended to represent air quality where people live, work and play. To
the extent that near-roadway monitoring occurs in areas where people
live, work or play, EPA encourages reporting of the AQI for that
specific sub-area of the MSA (64 FR 42548, August 4, 1999). We also
agree that it may be difficult to communicate this type of information
and we plan to work with State and local air agencies to figure out the
best way to present this information to the public using the AQI. Air
quality forecasting is recommended but not required (64 FR 42548,
August 4, 1999). EPA will work with State agencies that want to develop
a forecasting program.
    With regard to the proposed breakpoints, EPA received few comments.
The National Association of Clean Air Agencies commented that it would
be confusing to the public to have an AQI value of 50 set below the
level of the annual NO2 standard. We agree with this
comment, and therefore have decided that it is appropriate to set the
AQI value of 50, the breakpoint between the good and moderate ranges,
set at the numerical level of the annual standard, 53 ppb
NO2, 1-hour average. The AQI value of 100, the breakpoint
between the moderate and unhealthy for sensitive groups category, is
set at 100 ppb, 1-hour average, the level of the primary NO2
NAAQS. EPA is setting an AQI value of 150, the breakpoint between the
unhealthy for sensitive groups and unhealthy categories, at 0.360 ppm
NO2, 1-hour average.

VIII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is a ``significant regulatory action'' because it was deemed to
``raise novel legal or policy issues.'' Accordingly, EPA submitted this
action to the Office of Management and Budget (OMB) for review under
Executive Order 12866 and any changes made in response to OMB
recommendations have been documented in the docket for this action. In
addition, EPA prepared a Regulatory Impact Analysis (RIA) of the
potential costs and benefits associated with this action. However, the
CAA and judicial decisions make clear that the economic and technical
feasibility of attaining ambient standards are not to be considered in
setting or revising NAAQS, although such factors may be considered in
the development of State plans to implement the standards. Accordingly,
although an RIA has been prepared, the results of the RIA have not been
considered in developing this final rule.

B. Paperwork Reduction Act

    The information collection requirements in this final rule have
been submitted for approval to the Office of Management and Budget
(OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The
information collection requirements are not enforceable until OMB
approves them.
    The Information Collection Request (ICR) document prepared by EPA
for these revisions to part 58 has been assigned EPA ICR number
2358.02.
    The information collected under 40 CFR part 53 (e.g., test results,
monitoring records, instruction manual, and other associated
information) is needed to determine whether a candidate method intended
for use in determining attainment of the National Ambient Air Quality
Standards (NAAQS) in 40 CFR part 50 will meet

the design, performance, and/or comparability requirements for
designation as a Federal reference method (FRM) or Federal equivalent
method (FEM). We do not expect the number of FRM or FEM determinations
to increase over the number that is currently used to estimate burden
associated with NO2 FRM/FEM determinations provided in the
current ICR for 40 CFR part 53 (EPA ICR numbers 2358.01). As such, no
change in the burden estimate for 40 CFR part 53 has been made as part
of this rulemaking.
    The information collected and reported under 40 CFR part 58 is
needed to determine compliance with the NAAQS, to characterize air
quality and associated health impacts, to develop emissions control
strategies, and to measure progress for the air pollution program. The
amendments would revise the technical requirements for NO2
monitoring sites, require the siting and operation of additional
NO2 ambient air monitors, and the reporting of the collected
ambient NO2 monitoring data to EPA's Air Quality System
(AQS). The annual average reporting burden for the collection under 40
CFR part 58 (averaged over the first 3 years of this ICR) is
$3,261,007. Burden is defined at 5 CFR 1320.3(b). State, local, and
Tribal entities are eligible for State assistance grants provided by
the Federal government under the CAA which can be used for monitors and
related activities.
    An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this rule on small
entities, small entity is defined as: (1) A small business that is a
small industrial entity as defined by the Small Business
Administration's (SBA) regulations at 13 CFR 121.201; (2) a small
governmental jurisdiction that is a government of a city, county, town,
school district or special district with a population of less than
50,000; and (3) a small organization that is any not-for-profit
enterprise which is independently owned and operated and is not
dominant in its field.
    After considering the economic impacts of this 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 final
rule will not impose any requirements on small entities. Rather, this
rule establishes national standards for allowable concentrations of
NO2 in ambient air as required by section 109 of the CAA.
American Trucking Ass'ns v. EPA, 175 F.3d 1027, 1044-45 (DC cir. 1999)
(NAAQS do not have significant impacts upon small entities because
NAAQS themselves impose no regulations upon small entities). Similarly,
the amendments to 40 CFR part 58 address the requirements for States to
collect information and report compliance with the NAAQS and will not
impose any requirements on small entities.

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 revisions to the NO2 NAAQS impose no enforceable duty on
any State, local or Tribal governments or the private sector. The
expected costs associated with the monitoring requirements are
described in EPA's ICR document, but those costs are not expected to
exceed $100 million in the aggregate for any year. Furthermore, as
indicated previously, in setting a NAAQS EPA cannot consider the
economic or technological feasibility of attaining ambient air quality
standards. Because the Clean Air Act prohibits EPA from considering the
types of estimates and assessments described in section 202 when
setting the NAAQS, the UMRA does not require EPA to prepare a written
statement under section 202 for the revisions to the NO2
NAAQS. Thus, this rule is not subject to the requirements of sections
202 or 205 of UMRA.
    With regard to implementation guidance, the CAA imposes the
obligation for States to submit SIPs to implement the NO2
NAAQS. In this final rule, EPA is merely providing an interpretation of
those requirements. However, even if this rule did establish an
independent obligation for States to submit SIPs, it is questionable
whether an obligation to submit a SIP revision would constitute a
Federal mandate in any case. The obligation for a State to submit a SIP
that arises out of section 110 and section 191 of the CAA is not
legally enforceable by a court of law, and at most is a condition for
continued receipt of highway funds. Therefore, it is possible to view
an action requiring such a submittal as not creating any enforceable
duty within the meaning of 2 U.S.C. 658 for purposes of the UMRA. Even
if it did, the duty could be viewed as falling within the exception for
a condition of Federal assistance under 2 U.S.C. 658.
    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 because it imposes
no enforceable duty on any small governments.

E. Executive Order 13132: Federalism

    This action 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 rule does not alter the
relationship between the Federal government and the States regarding
the establishment and implementation of air quality improvement
programs as codified in the CAA. Under section 109 of the CAA, EPA is
mandated to establish NAAQS; however, CAA section 116 preserves the
rights of States to establish more stringent requirements if deemed
necessary by a State. Furthermore, this rule does not impact CAA
section 107 which establishes that the States have primary
responsibility for implementation of the NAAQS. Finally, as noted in
section E (above) on UMRA, this rule does not impose significant costs
on State, local, or Tribal governments or the private sector. Thus,
Executive Order 13132 does not apply to this rule.

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). It does not have
a substantial direct effect on one or more Indian Tribes, on the
relationship between the Federal government and Indian Tribes, or on
the distribution of power and responsibilities between the Federal
government and Tribes. The rule does not alter the relationship between
the

Federal government and Tribes as established in the CAA and the TAR.
Under section 109 of the CAA, EPA is mandated to establish NAAQS;
however, this rule does not infringe existing Tribal authorities to
regulate air quality under their own programs or under programs
submitted to EPA for approval. Furthermore, this rule does not affect
the flexibility afforded to Tribes in seeking to implement CAA programs
consistent with the TAR, nor does it impose any new obligation on
Tribes to adopt or implement any NAAQS. Finally, as noted in section E
(above) on UMRA, this rule does not impose significant costs on Tribal
governments. Thus, Executive Order 13175 does not apply to this action.

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

    This action is subject to Executive Order 13045 (62 FR 19885, April
23, 1997) because it is an economically significant regulatory action
as defined by Executive Order 12866, and EPA believes that the
environmental health or safety risk addressed by this action has a
disproportionate effect on children. The final rule will establish
uniform national ambient air quality standards for NO2;
these standards are designed to protect public health with an adequate
margin of safety, as required by CAA section 109. The protection
offered by these standards may be especially important for asthmatics,
including asthmatic children, because respiratory effects in asthmatics
are among the most sensitive health endpoints for NO2
exposure. Because asthmatic children are considered a sensitive
population, we have evaluated the potential health effects of exposure
to NO2 pollution among asthmatic children. These effects and
the size of the population affected are discussed in chapters 3 and 4
of the ISA; chapters 3, 4, and 8 of the REA, and sections II.A through
II.E of this preamble.

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, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355
(May 22, 2001)) because it is not likely to have a significant adverse
effect on the supply, distribution, or use of energy. The purpose of
this rule is to establish revised NAAQS for NO2. The rule
does not prescribe specific control strategies by which these ambient
standards will be met. Such strategies will be developed by States on a
case-by-case basis, and EPA cannot predict whether the control options
selected by States will include regulations on energy suppliers,
distributors, or users. Thus, EPA concludes that this rule is not
likely to have any adverse energy effects.

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 final rulemaking involves technical standards. Therefore the
Agency conducted a search to identify potential applicable voluntary
consensus standards. However, we identified no such standards, and none
were brought to our attention in comments. Therefore, EPA has decided
to use the technical standard described in Section III.A of the
preamble.

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

    Executive Order 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 effects on
any population, including any minority or low-income population. The
final rule will establish uniform national standards for NO2
in ambient air.

K. 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. EPA will submit a report containing this 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 rule in the Federal Register. A Major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is a ``major rule'' as defined by 5 U.S.C.
804(2). This rule will be effective on April 12, 2010.

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List of Subjects

40 CFR Part 50

    Environmental protection, Air pollution control, Carbon monoxide,
Lead, Nitrogen dioxide, Ozone, Particulate matter, Sulfur oxides.

40 CFR Part 58

    Environmental protection, Administrative practice and procedure,
Air pollution control, Intergovernmental relations, Reporting and
recordkeeping requirements.

    Dated: January 22, 2010.
Lisa P. Jackson,
Administrator.

0
For the reasons stated in the preamble, title 40, chapter I of the Code
of Federal Regulations is amended as follows:

PART 50--NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY
STANDARDS

0
1. The authority citation for part 50 continues to read as follows:

    Authority: 42 U.S.C. 7401, et seq.

0
2. Section 50.11 is revised to read as follows:

Sec.  50.11  National primary and secondary ambient air quality
standards for oxides of nitrogen (with nitrogen dioxide as the
indicator).

    (a) The level of the national primary annual ambient air quality
standard for oxides of nitrogen is 53 parts per billion (ppb, which is
1 part in 1,000,000,000), annual average concentration, measured in the
ambient air as nitrogen dioxide.
    (b) The level of the national primary 1-hour ambient air quality
standard for oxides of nitrogen is 100 ppb, 1-hour average
concentration, measured in the ambient air as nitrogen dioxide.
    (c) The level of the national secondary ambient air quality
standard for nitrogen dioxide is 0.053 parts per million (100
micrograms per cubic meter), annual arithmetic mean concentration.
    (d) The levels of the standards shall be measured by:
    (1) A reference method based on appendix F to this part; or
    (2) By a Federal equivalent method (FEM) designated in accordance
with part 53 of this chapter.
    (e) The annual primary standard is met when the annual average
concentration in a calendar year is less than or equal to 53 ppb, as
determined in accordance with Appendix S of this part for the annual
standard.
    (f) The 1-hour primary standard is met when the three-year average
of the annual 98th percentile of the daily maximum 1-hour average
concentration is less than or equal to 100 ppb, as determined in
accordance with Appendix S of this part for the 1-hour standard.
    (g) The secondary standard is attained when the annual arithmetic
mean concentration in a calendar year is less than or equal to 0.053
ppm, rounded to three decimal places (fractional parts equal to or
greater than 0.0005 ppm must be rounded up). To demonstrate attainment,
an annual mean must be based upon hourly data that are at least 75
percent complete or upon data derived from manual methods that are at
least 75 percent complete for the scheduled sampling days in each
calendar quarter.

0
3. Section 50.14 is amended by adding an entry to the end of table in
paragraph (c)(2)(vi) to read as follows:

Sec.  50.14  Treatment of air quality monitoring data influenced by
exceptional events.

* * * * *
    (c) * * *
    (2) * * *
    (vi) * * *

      Table 1--Schedule for Exceptional Event Flagging and Documentation Submission for Data To Be Used in
                                 Designations Decisions for New or Revised NAAQS
----------------------------------------------------------------------------------------------------------------
                                         Air quality
 NAAQS pollutant/ standard/ (level)/   data collected  Event flagging & initial       Detailed documentation
          promulgation date             for calendar     description deadline          submission deadline
                                            year
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
NO2/1-Hour Standard (100 PPB)........            2008  July 1, 2010 \a\........  January 22, 2011.
                                                 2009  July 1, 2010............  January 22, 2011.
                                                 2010  April 1, 2011 \a\.......  July 1, 2011 \a\.
----------------------------------------------------------------------------------------------------------------
\a\ Indicates change from general schedule in 40 CFR 50.14.
Note: EPA notes that the table of revised deadlines only applies to data EPA will use to establish the final
  initial designations for new or revised NAAQS. The general schedule applies for all other purposes, most
  notably, for data used by EPA for redesignations to attainment.

* * * * *

0
4. Appendix S to Part 50 is added to read as follows:

Appendix S to Part 50--Interpretation of the Primary National Ambient
Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide)

1. General

    (a) This appendix explains the data handling conventions and
computations necessary for determining when the primary national
ambient air quality standards for oxides of nitrogen as measured by
nitrogen dioxide (``NO2 NAAQS'') specified in 50.11 are
met. Nitrogen dioxide (NO2) is measured in the ambient
air by a Federal reference method (FRM) based on appendix F to this
part or by a Federal equivalent method (FEM) designated in
accordance with part 53 of this chapter. Data handling and
computation procedures to be used in making comparisons between
reported NO2 concentrations and the levels of the
NO2 NAAQS are specified in the following sections.
    (b) Whether to exclude, retain, or make adjustments to the data
affected by exceptional events, including natural events, is
determined by the requirements and process deadlines specified in
50.1, 50.14 and 51.930 of this chapter.
    (c) The terms used in this appendix are defined as follows:
    Annual mean refers to the annual average of all of the 1-hour
concentration values as defined in section 5.1 of this appendix.
    Daily maximum 1-hour values for NO2 refers to the
maximum 1-hour NO2 concentration values measured from
midnight to midnight (local standard time) that are used in NAAQS
computations.
    Design values are the metrics (i.e., statistics) that are
compared to the NAAQS levels to determine compliance, calculated as
specified in section 5 of this appendix. The design values for the
primary NAAQS are:
    (1) The annual mean value for a monitoring site for one year
(referred to as the ``annual primary standard design value'').
    (2) The 3-year average of annual 98th percentile daily maximum
1-hour values for a monitoring site (referred to as the ``1-hour
primary standard design value'').
    98th percentile daily maximum 1-hour value is the value below
which nominally 98 percent of all daily maximum 1-hour concentration
values fall, using the ranking and selection method specified in
section 5.2 of this appendix.
    Quarter refers to a calendar quarter.
    Year refers to a calendar year.

2. Requirements for Data Used for Comparisons With the NO2
NAAQS and Data Reporting Considerations

    (a) All valid FRM/FEM NO2 hourly data required to be
submitted to EPA's Air Quality System (AQS), or otherwise available
to EPA, meeting the requirements of part 58 of this chapter
including appendices A, C, and E shall be used in design value
calculations. Multi-hour average concentration values collected by
wet chemistry methods shall not be used.
    (b) When two or more NO2 monitors are operated at a
site, the State may in advance designate one of them as the primary
monitor. If the State has not made this designation, the
Administrator will make the designation, either in advance or
retrospectively. Design values will be developed using only the data
from the primary monitor, if this results in a valid design value.
If data from the primary monitor do not allow the development of a
valid design value, data solely from the other monitor(s) will be
used in turn to develop a valid design value, if this results in a
valid design value. If there are three or more monitors, the order
for such comparison of the other monitors will be determined by the
Administrator. The Administrator may combine data from different
monitors in different years for the purpose of developing a valid 1-
hour primary standard design value, if a valid design value cannot
be developed solely with the data from a single monitor. However,
data from two or more monitors in the same year at the same site
will not be combined in an attempt to meet data completeness
requirements, except if one monitor has physically replaced another
instrument permanently, in which case the two instruments will be
considered to be the same monitor, or if the State has switched the
designation of the primary monitor from one instrument to another
during the year.
    (c) Hourly NO2 measurement data shall be reported to
AQS in units of parts per billion (ppb), to at most one place after
the decimal, with additional digits to the right being truncated
with no further rounding.

3. Comparisons With the NO2 NAAQS

3.1 The Annual Primary NO2 NAAQS

    (a) The annual primary NO2 NAAQS is met at a site
when the valid annual primary standard design value is less than or
equal to 53 parts per billion (ppb).
    (b) An annual primary standard design value is valid when at
least 75 percent of the hours in the year are reported.
    (c) An annual primary standard design value based on data that
do not meet the completeness criteria stated in section 3.1(b) may
also be considered valid with the approval of, or at the initiative
of, the Administrator, who may consider factors such as monitoring
site closures/moves, monitoring diligence, the consistency and
levels of the valid concentration measurements that are available,
and nearby concentrations in determining whether to use such data.
    (d) The procedures for calculating the annual primary standard
design values are given in section 5.1 of this appendix.

3.2 The 1-hour Primary NO2 NAAQS

    (a) The 1-hour primary NO2 NAAQS is met at a site
when the valid 1-hour primary standard design value is less than or
equal to 100 parts per billion (ppb).
    (b) An NO2 1-hour primary standard design value is
valid if it encompasses three consecutive calendar years of complete
data. A year meets data completeness requirements when all 4
quarters are complete. A quarter is complete when at least 75
percent of the sampling days for each quarter have complete data. A
sampling day has complete data if 75 percent of the hourly
concentration values, including State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator, are reported.
    (c) In the case of one, two, or three years that do not meet the
completeness requirements of section 3.2(b) of this appendix and
thus would normally not be useable for the calculation of a valid 3-
year 1-hour primary standard design value, the 3-year 1-hour primary
standard design value shall nevertheless be considered valid if one
of the following conditions is true.
    (i) At least 75 percent of the days in each quarter of each of
three consecutive years have at least one reported hourly value, and
the design value calculated according to the procedures specified in
section 5.2 is above the level of the primary 1-hour standard.
    (ii)(A) A 1-hour primary standard design value that is below the
level of the NAAQS can be validated if the substitution test in
section 3.2(c)(ii)(B) results in a ``test design value'' that is
below the level of the NAAQS. The test substitutes actual ``high''
reported daily maximum 1-hour values from the same site at about the
same time of the year (specifically, in the same calendar quarter)
for unknown values that were not successfully measured. Note that
the test is merely diagnostic in nature, intended to confirm that
there is a very high likelihood that the original design value (the
one with less than 75 percent data capture of hours by day and of
days by quarter) reflects the true under-NAAQS-level status for that
3-year period; the result of this data substitution test (the ``test
design value'', as defined in section 3.2(c)(ii)(B)) is not
considered the actual design value. For this test, substitution is
permitted only if there are at least 200 days across the three
matching quarters of the three years under consideration (which is
about 75 percent of all possible daily values in those three
quarters) for which 75 percent of the hours in the day, including
State-flagged data affected by exceptional events which have been
approved for exclusion by the Administrator, have reported
concentrations. However, maximum 1-hour values from days with less
than 75 percent of the hours reported shall also be considered in
identifying the high value to be used for substitution.
    (B) The substitution test is as follows: Data substitution will
be performed in all quarter periods that have less than 75 percent
data capture but at least 50 percent data capture, including State-
flagged data affected by exceptional events which have been approved
for exclusion by the Administrator; if any quarter has less than 50
percent data capture then this substitution test cannot be used.
Identify for each quarter (e.g., January-March) the highest reported
daily maximum 1-hour value for that quarter, excluding State-flagged
data affected by exceptional events which have been approved for
exclusion by the Administrator, looking across those three months of
all three years under consideration. All daily maximum 1-hour values
from all days in the quarter period shall be considered when
identifying this highest value, including days with less than

75 percent data capture. If after substituting the highest non-
excluded reported daily maximum 1-hour value for a quarter for as
much of the missing daily data in the matching deficient quarter(s)
as is needed to make them 100 percent complete, the procedure in
section 5.2 yields a recalculated 3-year 1-hour standard ``test
design value'' below the level of the standard, then the 1-hour
primary standard design value is deemed to have passed the
diagnostic test and is valid, and the level of the standard is
deemed to have been met in that 3-year period. As noted in section
3.2(c)(i), in such a case, the 3-year design value based on the data
actually reported, not the ``test design value'', shall be used as
the valid design value.
    (iii)(A) A 1-hour primary standard design value that is above
the level of the NAAQS can be validated if the substitution test in
section 3.2(c)(iii)(B) results in a ``test design value'' that is
above the level of the NAAQS. The test substitutes actual ``low''
reported daily maximum 1-hour values from the same site at about the
same time of the year (specifically, in the same three months of the
calendar) for unknown values that were not successfully measured.
Note that the test is merely diagnostic in nature, intended to
confirm that there is a very high likelihood that the original
design value (the one with less than 75 percent data capture of
hours by day and of days by quarter) reflects the true above-NAAQS-
level status for that 3-year period; the result of this data
substitution test (the ``test design value'', as defined in section
3.2(c)(iii)(B)) is not considered the actual design value. For this
test, substitution is permitted only if there are a minimum number
of available daily data points from which to identify the low
quarter-specific daily maximum 1-hour values, specifically if there
are at least 200 days across the three matching quarters of the
three years under consideration (which is about 75 percent of all
possible daily values in those three quarters) for which 75 percent
of the hours in the day have reported concentrations. Only days with
at least 75 percent of the hours reported shall be considered in
identifying the low value to be used for substitution.
    (B) The substitution test is as follows: Data substitution will
be performed in all quarter periods that have less than 75 percent
data capture. Identify for each quarter (e.g., January-March) the
lowest reported daily maximum 1-hour value for that quarter, looking
across those three months of all three years under consideration.
All daily maximum 1-hour values from all days with at least 75
percent capture in the quarter period shall be considered when
identifying this lowest value. If after substituting the lowest
reported daily maximum 1-hour value for a quarter for as much of the
missing daily data in the matching deficient quarter(s) as is needed
to make them 75 percent complete, the procedure in section 5.2
yields a recalculated 3-year 1-hour standard ``test design value''
above the level of the standard, then the 1-hour primary standard
design value is deemed to have passed the diagnostic test and is
valid, and the level of the standard is deemed to have been exceeded
in that 3-year period. As noted in section 3.2(c)(i), in such a
case, the 3-year design value based on the data actually reported,
not the ``test design value'', shall be used as the valid design
value.
    (d) A 1-hour primary standard design value based on data that do
not meet the completeness criteria stated in 3.2(b) and also do not
satisfy section 3.2(c), may also be considered valid with the
approval of, or at the initiative of, the Administrator, who may
consider factors such as monitoring site closures/moves, monitoring
diligence, the consistency and levels of the valid concentration
measurements that are available, and nearby concentrations in
determining whether to use such data.
    (e) The procedures for calculating the 1-hour primary standard
design values are given in section 5.2 of this appendix.

4. Rounding Conventions

4.1 Rounding Conventions for the Annual Primary NO2
NAAQS

    (a) Hourly NO2 measurement data shall be reported to
AQS in units of parts per billion (ppb), to at most one place after
the decimal, with additional digits to the right being truncated
with no further rounding.
    (b) The annual primary standard design value is calculated
pursuant to section 5.1 and then rounded to the nearest whole number
or 1 ppb (decimals 0.5 and greater are rounded up to the nearest
whole number, and any decimal lower than 0.5 is rounded down to the
nearest whole number).

4.2 Rounding Conventions for the 1-hour Primary NO2 NAAQS

    (a) Hourly NO2 measurement data shall be reported to
AQS in units of parts per billion (ppb), to at most one place after
the decimal, with additional digits to the right being truncated
with no further rounding.
    (b) Daily maximum 1-hour values are not rounded.
    (c) The 1-hour primary standard design value is calculated
pursuant to section 5.2 and then rounded to the nearest whole number
or 1 ppb (decimals 0.5 and greater are rounded up to the nearest
whole number, and any decimal lower than 0.5 is rounded down to the
nearest whole number).

5. Calculation Procedures for the Primary NO2 NAAQS

5.1 Procedures for the Annual Primary NO2 NAAQS

    (a) When the data for a site and year meet the data completeness
requirements in section 3.1(b) of this appendix, or if the
Administrator exercises the discretionary authority in section
3.1(c), the annual mean is simply the arithmetic average of all of
the reported 1-hour values.
    (b) The annual primary standard design value for a site is the
valid annual mean rounded according to the conventions in section
4.1.

5.2 Calculation Procedures for the 1-hour Primary NO2 NAAQS

    (a) Procedure for identifying annual 98th percentile values.
When the data for a particular site and year meet the data
completeness requirements in section 3.2(b), or if one of the
conditions of section 3.2(c) is met, or if the Administrator
exercises the discretionary authority in section 3.2(d),
identification of annual 98th percentile value is accomplished as
follows.
    (i) The annual 98th percentile value for a year is the higher of
the two values resulting from the following two procedures.
    (1) Procedure 1.
    (A) For the year, determine the number of days with at least 75
percent of the hourly values reported including State-flagged data
affected by exceptional events which have been approved for
exclusion by the Administrator.
    (B) For the year, from only the days with at least 75 percent of
the hourly values reported, select from each day the maximum hourly
value excluding State-flagged data affected by exceptional events
which have been approved for exclusion by the Administrator.
    (C) Sort all these daily maximum hourly values from a particular
site and year by descending value. (For example: (x[1], x[2], x[3],
* * *, x[n]). In this case, x[1] is the largest number and x[n] is
the smallest value.) The 98th percentile is determined from this
sorted series of daily values which is ordered from the highest to
the lowest number. Using the left column of Table 1, determine the
appropriate range (i.e., row) for the annual number of days with
valid data for year y (cny) as determined from step (A).
The corresponding ``n'' value in the right column identifies the
rank of the annual 98th percentile value in the descending sorted
list of daily site values for year y. Thus, P0.98, y =
the nth largest value.
    (2) Procedure 2.
    (A) For the year, determine the number of days with at least one
hourly value reported including State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator.
    (B) For the year, from all the days with at least one hourly
value reported, select from each day the maximum hourly value
excluding State-flagged data affected by exceptional events which
have been approved for exclusion by the Administrator.
    (C) Sort all these daily maximum values from a particular site
and year by descending value. (For example: (x[1], x[2], x[3], * *
*, x[n]). In this case, x[1] is the largest number and x[n] is the
smallest value.) The 98th percentile is determined from this sorted
series of daily values which is ordered from the highest to the
lowest number. Using the left column of Table 1, determine the
appropriate range (i.e., row) for the annual number of days with
valid data for year y (cny) as determined from step (A).
The corresponding ``n'' value in the right column identifies the
rank of the annual 98th percentile value in the descending sorted
list of daily site values for year y. Thus, P0.98, y =
the nth largest value.
    (b) The 1-hour primary standard design value for a site is mean
of the three annual 98th percentile values, rounded according to the
conventions in section 4.

                                 Table 1
------------------------------------------------------------------------
                                                        P0.98, y is the
                                                      nth maximum  value
  Annual number  of days with  valid data for  year      of the  year,
                     ``y'' (cny)                        where n  is the
                                                        listed  number
------------------------------------------------------------------------
1-50................................................                  1
51-100..............................................                  2
101-150.............................................                  3
151-200.............................................                  4
201-250.............................................                  5
251-300.............................................                  6
301-350.............................................                  7
351-366.............................................                  8
------------------------------------------------------------------------

PART 58--AMBIENT AIR QUALITY SURVEILLANCE

0
5. The authority citation for part 58 continues to read as follows:

    Authority: 42 U.S.C. 7403, 7410, 7601(a), 7611, and 7619.

Subpart A--[Amended]

0
6. Section 58.1, is amended by adding the definitions for ``AADT'' and
``Near-road NO2 Monitor'' in alphabetical order to read as
follows:

Sec.  58.1  Definitions

* * * * *
    AADT means the annual average daily traffic.
    * * *
    Near-road NO2 Monitor means any NO2 monitor meeting the
specifications in 4.3.2 of Appendix D and paragraphs 2, 4(d), 6.1, and
6.4 of Appendix E of this part.
* * * * *

Subpart B [Amended]

0
7. Section 58.10, is amended by adding paragraphs (a)(5) and (b)(12) to
read as follows:

Sec.  58.10  Annual monitoring network plan and periodic network
assessment.

    (a) * * *
    (5) A plan for establishing NO2 monitoring sites in
accordance with the requirements of appendix D to this part shall be
submitted to the Administrator by July 1, 2012. The plan shall provide
for all required monitoring stations to be operational by January 1,
2013.
* * * * *
    (b) * * *
    (12) The identification of required NO2 monitors as
either near-road or area-wide sites in accordance with Appendix D,
Section 4.3 of this part.
* * * * *

0
8. Section 58.13 is amended by adding paragraph (c) to read as follows:

Sec.  58.13  Monitoring network completion.

* * * * *
    (c) The network of NO2 monitors must be physically
established no later than January 1, 2013, and at that time, must be
operating under all of the requirements of this part, including the
requirements of appendices A, C, D, and E to this part.

0
9. Section 58.16 is amended by revising paragraph (a) to read as
follows:

Sec.  58.16  Data submittal and archiving requirements.

* * * * *
    (a) The State, or where appropriate, local agency, shall report to
the Administrator, via AQS all ambient air quality data and associated
quality assurance data for SO2; CO; O3;
NO2; NO; NOY; NOX; Pb-TSP mass
concentration; Pb-PM10 mass concentration; PM10
mass concentration; PM2.5mass concentration; for filter-
based PM2.5FRM/FEM the field blank mass, sampler-generated
average daily temperature, and sampler-generated average daily
pressure; chemically speciated PM2.5 mass concentration
data; PM10-2.5 mass concentration; chemically speciated
PM10-2.5 mass concentration data; meteorological data from
NCore and PAMS sites; average daily temperature and average daily
pressure for Pb sites if not already reported from sampler generated
records; and metadata records and information specified by the AQS Data
Coding Manual (http://www.epa.gov/ttn/airs/airsaqs/manuals/
manuals.htm). The State, or where appropriate, local agency, may report
site specific meteorological measurements generated by onsite equipment
(meteorological instruments, or sampler generated) or measurements from
the nearest airport reporting ambient pressure and temperature. Such
air quality data and information must be submitted directly to the AQS
via electronic transmission on the specified quarterly schedule
described in paragraph (b) of this section.
* * * * *

0
10. Appendix A to Part 58 is amended by adding paragraph <IP_ADDRESS> to
read as follows:

Appendix A to Part 58--Quality Assurance Requirements for SLAMS, SPMs
and PSD Air Monitoring

* * * * *
    <IP_ADDRESS> Measurement Uncertainty for NO2. The goal for
acceptable measurement uncertainty is defined for precision as an
upper 90 percent confidence limit for the coefficient of variation
(CV) of 15 percent and for bias as an upper 95 percent confidence
limit for the absolute bias of 15 percent.
* * * * *

0
11. Appendix C to Part 58 is amended by adding paragraph 2.1.1 to read
as follows:

Appendix C to Part 58--Ambient Air Quality Monitoring Methodology

* * * * *
    2.1.1 Any NO2 FRM or FEM used for making primary
NAAQS decisions must be capable of providing hourly averaged
concentration data.
* * * * *

0
12. Appendix D to Part 58 is amended by revising paragraph 4.3 to read
as follows:

Appendix D to Part 58--Network Design Criteria for Ambient Air Quality
Monitoring

* * * * *

4.3 Nitrogen Dioxide (NO2) Design Criteria

4.3.1 General Requirements

    (a) State and, where appropriate, local agencies must operate a
minimum number of required NO2 monitoring sites as
described below.

4.3.2 Requirement for Near-road NO2 Monitors

    (a) Within the NO2 network, there must be one
microscale near-road NO2 monitoring station in each CBSA
with a population of 500,000 or more persons to monitor a location
of expected maximum hourly concentrations sited near a major road
with high AADT counts as specified in paragraph 4.3.2(a)(1) of this
appendix. An additional near-road NO2 monitoring station
is required for any CBSA with a population of 2,500,000 persons or
more, or in any CBSA with a population of 500,000 or more persons
that has one or more roadway segments with 250,000 or greater AADT
counts to monitor a second location of expected maximum hourly
concentrations. CBSA populations shall be based on the latest
available census figures.
    (1) The near-road NO2 monitoring stations shall be
selected by ranking all road segments within a CBSA by AADT and then
identifying a location or locations adjacent to those highest ranked
road segments, considering fleet mix, roadway design, congestion
patterns, terrain, and meteorology, where maximum hourly
NO2 concentrations are expected to occur and siting
criteria can be met in accordance with appendix E of this part.
Where a State or local air monitoring agency identifies multiple
acceptable candidate sites where maximum hourly NO2
concentrations are expected to occur, the monitoring agency shall
consider the potential for population exposure in the criteria
utilized to select the final site location. Where one CBSA is
required to have two near-road NO2 monitoring stations,
the sites shall be differentiated from each other by one or more of
the following factors: fleet mix; congestion patterns; terrain;
geographic area within the

CBSA; or different route, interstate, or freeway designation.
    (b) Measurements at required near-road NO2 monitor
sites utilizing chemiluminescence FRMs must include at a minimum:
NO, NO2, and NOX.

4.3.3 Requirement for Area-wide NO2 Monitoring

    (a) Within the NO2 network, there must be one
monitoring station in each CBSA with a population of 1,000,000 or
more persons to monitor a location of expected highest
NO2 concentrations representing the neighborhood or
larger spatial scales. PAMS sites collecting NO2 data
that are situated in an area of expected high NO2
concentrations at the neighborhood or larger spatial scale may be
used to satisfy this minimum monitoring requirement when the
NO2 monitor is operated year round. Emission inventories
and meteorological analysis should be used to identify the
appropriate locations within a CBSA for locating required area-wide
NO2 monitoring stations. CBSA populations shall be based
on the latest available census figures.

4.3.4 Regional Administrator Required Monitoring

    (a) The Regional Administrators, in collaboration with States,
must require a minimum of forty additional NO2 monitoring
stations nationwide in any area, inside or outside of CBSAs, above
the minimum monitoring requirements, with a primary focus on siting
these monitors in locations to protect susceptible and vulnerable
populations. The Regional Administrators, working with States, may
also consider additional factors described in paragraph (b) below to
require monitors beyond the minimum network requirement.
    (b) The Regional Administrators may require monitors to be sited
inside or outside of CBSAs in which:
    (i) The required near-road monitors do not represent all
locations of expected maximum hourly NO2 concentrations
in an area and NO2 concentrations may be approaching or
exceeding the NAAQS in that area;
    (ii) Areas that are not required to have a monitor in accordance
with the monitoring requirements and NO2 concentrations
may be approaching or exceeding the NAAQS; or
    (iii) The minimum monitoring requirements for area-wide monitors
are not sufficient to meet monitoring objectives.
    (c) The Regional Administrator and the responsible State or
local air monitoring agency should work together to design and/or
maintain the most appropriate NO2 network to address the
data needs for an area, and include all monitors under this
provision in the annual monitoring network plan.

4.3.5 NO2 Monitoring Spatial Scales

    (a) The most important spatial scale for near-road
NO2 monitoring stations to effectively characterize the
maximum expected hourly NO2 concentration due to mobile
source emissions on major roadways is the microscale. The most
important spatial scales for other monitoring stations
characterizing maximum expected hourly NO2 concentrations
are the microscale and middle scale. The most important spatial
scale for area-wide monitoring of high NO2 concentrations
is the neighborhood scale.
    (1) Microscale--This scale represents areas in close proximity
to major roadways or point and area sources. Emissions from roadways
result in high ground level NO2 concentrations at the
microscale, where concentration gradients generally exhibit a marked
decrease with increasing downwind distance from major roads. As
noted in appendix E of this part, near-road NO2
monitoring stations are required to be within 50 meters of target
road segments in order to measure expected peak concentrations.
Emissions from stationary point and area sources, and non-road
sources may, under certain plume conditions, result in high ground
level concentrations at the microscale. The microscale typically
represents an area impacted by the plume with dimensions extending
up to approximately 100 meters.
    (2) Middle scale--This scale generally represents air quality
levels in areas up to several city blocks in size with dimensions on
the order of approximately 100 meters to 500 meters. The middle
scale may include locations of expected maximum hourly
concentrations due to proximity to major NO2 point, area,
and/or non-road sources.
    (3) Neighborhood scale--The neighborhood scale represents air
quality conditions throughout some relatively uniform land use areas
with dimensions in the 0.5 to 4.0 kilometer range. Emissions from
stationary point and area sources may, under certain plume
conditions, result in high NO2 concentrations at the
neighborhood scale. Where a neighborhood site is located away from
immediate NO2 sources, the site may be useful in
representing typical air quality values for a larger residential
area, and therefore suitable for population exposure and trends
analyses.
    (4) Urban scale--Measurements in this scale would be used to
estimate concentrations over large portions of an urban area with
dimensions from 4 to 50 kilometers. Such measurements would be
useful for assessing trends in area-wide air quality, and hence, the
effectiveness of large scale air pollution control strategies. Urban
scale sites may also support other monitoring objectives of the
NO2 monitoring network identified in paragraph 4.3.4
above.

4.3.6 NOy Monitoring

    (a) NO/NOy measurements are included within the NCore
multi-pollutant site requirements and the PAMS program. These NO/
NOy measurements will produce conservative estimates for
NO2 that can be used to ensure tracking continued
compliance with the NO2 NAAQS. NO/NOy monitors
are used at these sites because it is important to collect data on
total reactive nitrogen species for understanding O3
photochemistry.
* * * * *

0
13. Appendix E to Part 58 is amended as follows:
0
a. By revising paragraphs 2, and 6.1.
0
b. By adding paragraphs 4(d) and 6.4.
0
c. By revising paragraphs 9(c), 11 and Table E-4.

Appendix E to Part 58--Probe and Monitoring Path Siting Criteria for
Ambient Air Quality Monitoring

* * * * *

2. Horizontal and Vertical Placement

    The probe or at least 80 percent of the monitoring path must be
located between 2 and 15 meters above ground level for all ozone and
sulfur dioxide monitoring sites, and for neighborhood or larger
spatial scale Pb, PM10, PM10-2.5,
PM2.5, NO2 and carbon monoxide sites. Middle
scale PM10-2.5 sites are required to have sampler inlets
between 2 and 7 meters above ground level. Microscale Pb,
PM10, PM10-2.5 and PM2.5 sites are
required to have sampler inlets between 2 and 7 meters above ground
level. Microscale near-road NO2 monitoring sites are
required to have sampler inlets between 2 and 7 meters above ground
level. The inlet probes for microscale carbon monoxide monitors that
are being used to measure concentrations near roadways must be
3\1/2\ meters above ground level. The probe or at least
90 percent of the monitoring path must be at least 1 meter
vertically or horizontally away from any supporting structure,
walls, parapets, penthouses, etc., and away from dusty or dirty
areas. If the probe or a significant portion of the monitoring path
is located near the side of a building or wall, then it should be
located on the windward side of the building relative to the
prevailing wind direction during the season of highest concentration
potential for the pollutant being measured.
* * * * *

4. * * *

    (d) For near-road NO2 monitoring stations, the
monitor probe shall have an unobstructed air flow, where no
obstacles exist at or above the height of the monitor probe, between
the monitor probe and the outside nearest edge of the traffic lanes
of the target road segment.
* * * * *

6. * * *

6.1 Spacing for Ozone Probes and Monitoring Paths

    In siting an O3 analyzer, it is important to minimize
destructive interferences form sources of NO, since NO readily
reacts with O3. Table E-1 of this appendix provides the
required minimum separation distances between a roadway and a probe
or, where applicable, at least 90 percent of a monitoring path for
various ranges of daily roadway traffic. A sampling site having a
point analyzer probe located closer to a roadway than allowed by the
Table E-1 requirements should be classified as microscale or middle
scale, rather than neighborhood or urban scale, since the
measurements from such a site would more closely represent the
middle scale. If an open path analyzer is used at a site, the
monitoring path(s) must not cross over a roadway with an average
daily traffic count of 10,000 vehicles per day or more. For those
situations where a monitoring path crosses a roadway with fewer than
10,000 vehicles per day, monitoring agencies must consider the
entire segment of the monitoring

path in the area of potential atmospheric interference from
automobile emissions. Therefore, this calculation must include the
length of the monitoring path over the roadway plus any segments of
the monitoring path that lie in the area between the roadway and
minimum separation distance, as determined from the Table E-1 of
this appendix. The sum of these distances must not be greater than
10 percent of the total monitoring path length.
* * * * *

6.4 Spacing for Nitrogen Dioxide (NO2) Probes and
Monitoring Paths

    (a) In siting near-road NO2 monitors as required in
paragraph 4.3.2 of appendix D of this part, the monitor probe shall
be as near as practicable to the outside nearest edge of the traffic
lanes of the target road segment; but shall not be located at a
distance greater than 50 meters, in the horizontal, from the outside
nearest edge of the traffic lanes of the target road segment.
    (b) In siting NO2 monitors for neighborhood and
larger scale monitoring, it is important to minimize near-road
influences. Table E-1 of this appendix provides the required minimum
separation distances between a roadway and a probe or, where
applicable, at least 90 percent of a monitoring path for various
ranges of daily roadway traffic. A sampling site having a point
analyzer probe located closer to a roadway than allowed by the Table
E-1 requirements should be classified as microscale or middle scale
rather than neighborhood or urban scale. If an open path analyzer is
used at a site, the monitoring path(s) must not cross over a roadway
with an average daily traffic count of 10,000 vehicles per day or
more. For those situations where a monitoring path crosses a roadway
with fewer than 10,000 vehicles per day, monitoring agencies must
consider the entire segment of the monitoring path in the area of
potential atmospheric interference form automobile emissions.
Therefore, this calculation must include the length of the
monitoring path over the roadway plus any segments of the monitoring
path that lie in the area between the roadway and minimum separation
distance, as determined form the Table E-1 of this appendix. The sum
of these distances must not be greater than 10 percent of the total
monitoring path length.
* * * * *

9. * * *

    (c) No matter how nonreactive the sampling probe material is
initially, after a period of use reactive particulate matter is
deposited on the probe walls. Therefore, the time it takes the gas
to transfer from the probe inlet to the sampling device is also
critical. Ozone in the presence of nitrogen oxide (NO) will show
significant losses even in the most inert probe material when the
residence time exceeds 20 seconds.\26\ Other studies \27-28\
indicate that a 10 second or less residence time is easily
achievable. Therefore, sampling probes for reactive gas monitors at
NCore and at NO2 sites must have a sample residence time
less than 20 seconds.
* * * * *

11. Summary

    Table E-4 of this appendix presents a summary of the general
requirements for probe and monitoring path siting criteria with
respect to distances and heights. It is apparent from Table E-4 that
different elevation distances above the ground are shown for the
various pollutants. The discussion in this appendix for each of the
pollutants describes reasons for elevating the monitor, probe, or
monitoring path. The differences in the specified range of heights
are based on the vertical concentration gradients. For CO and near-
road NO2 monitors, the gradients in the vertical
direction are very large for the microscale, so a small range of
heights are used. The upper limit of 15 meters is specified for the
consistency between pollutants and to allow the use of a single
manifold or monitoring path for monitoring more than one pollutant.

                                Table E-4 of Appendix E to Part 58. Summary of Probe and Monitoring Path Siting Criteria
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Horizontal and
                                                                                vertical distance
                                         Scale (maximum       Height from ground to     from supporting      Distance from trees       Distance from
             Pollutant                   monitoring path     probe, inlet or 80% of     structures\2\ to      to probe, inlet or     roadways to probe,
                                         length, meters)       monitoring path \1\    probe, inlet or 90%     90% of monitoring     inlet or monitoring
                                                                                of monitoring path\1\     path\1\ (meters)       path\1\ (meters)
                                                                                (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2 3,4,5,6........................  Middle (300 m)          2-15..................  >1...................  >10..................  N/A
                                      Neighborhood Urban,
                                      and Regional (1 km).
CO 4,5,7...........................  Micro, middle (300 m),  3\1/2\: 2-15..........  >1...................  >10..................  2-10; see Table E-2
                                      Neighborhood (1 km).                                                                          of this appendix for
                                                                                middle and
                                                                                neighborhood scales.
O3 3,4,5...........................  Middle (300 m)          2-15..................  >1...................  >10..................  See Table E-1 of this
                                      Neighborhood, Urban,                                                                          appendix for all
                                      and Regional (1 km).                                                                          scales.
NO2 3,4,5..........................  Micro (Near-road [50-   2-7 (micro);..........  >1...................  >10..................  <=50 meters for near-
                                      300]).                                                                                road microscale.
                                     Middle (300m).........  2-15 (all other         .....................  .....................
                                                              scales).
                                     Neighborhood, Urban,    ......................  .....................  .....................  See Table E-1 of this
                                      and Regional (1 km).                                                                          appendix for all
                                                                                other scales
Ozone precursors (for PAMS) 3 4 5..  Neighborhood and Urban  2-15..................  >1...................  >10..................  See Table E-4 of this
                                      (1 km).                                                                                appendix for all
                                                                                scales.
PM, Pb 3,4,5,6,8...................  Micro: Middle,          2-7 (micro); 2-7        >2 (all scales,        >10 (all scales).....  2-10 (micro); see
                                      Neighborhood, Urban     (middle PM10	2.5); 2-   horizontal distance                           Figure E-1 of this
                                      and Regional.           15 (all other scales).  only).                                        appendix for all
                                                                                other scales.
--------------------------------------------------------------------------------------------------------------------------------------------------------
N/A--Not applicable.
\1\ Monitoring path for open path analyzers is applicable only to middle or neighborhood scale CO monitoring, middle, neighborhood, urban, and regional
  scale NO2 monitoring, and all applicable scales for monitoring SO2,O3, and O3 precursors.
\2\ When probe is located on a rooftop, this separation distance is in reference to walls, parapets, or penthouses located on roof.
\3\ Should be >20 meters from the dripline of tree(s) and must be 10 meters from the dripline when the tree(s) act as an obstruction.
\4\ Distance from sampler, probe, or 90% of monitoring path to obstacle, such as a building, must be at least twice the height the obstacle protrudes
  above the sampler, probe, or monitoring path. Sites not meeting this criterion may be classified as middle scale (see text).
\5\ Must have unrestricted airflow 270 degrees around the probe or sampler; 180 degrees if the probe is on the side of a building or a wall.

\6\ The probe, sampler, or monitoring path should be away from minor sources, such as furnace or incineration flues. The separation distance is
  dependent on the height of the minor source's emission point (such as a flue), the type of fuel or waste burned, and the quality of the fuel (sulfur,
  ash, or lead content). This criterion is designed to avoid undue influences from minor sources.
\7\ For microscale CO monitoring sites, the probe must be >10 meters from a street intersection and preferably at a midblock location.
\8\ Collocated monitors must be within 4 meters of each other and at least 2 meters apart for flow rates greater than 200 liters/min or at least 1 meter
  apart for samplers having flow rates less than 200 liters/min to preclude airflow interference.

* * * * *
    14. Appendix G to Part 58 is amended as by revising paragraph 9 and
Table 2 to read as follows:

Appendix G to Part 58--Uniform Air Quality Index (AQI) and Daily
Reporting

* * * * *

9. How Does the AQI Relate to Air Pollution Levels?

    For each pollutant, the AQI transforms ambient concentrations to
a scale from 0 to 500. The AQI is keyed as appropriate to the
national ambient air quality standards (NAAQS) for each pollutant.
In most cases, the index value of 100 is associated with the
numerical level of the short-term (i.e., averaging time of 24-hours
or less) standard for each pollutant. The index value of 50 is
associated with one of the following: the numerical level of the
annual standard for a pollutant, if there is one; one-half the level
of the short-term standard for the pollutant; or the level at which
it is appropriate to begin to provide guidance on cautionary
language. Higher categories of the index are based on increasingly
serious health effects that affect increasing proportions of the
population. An index value is calculated each day for each pollutant
(as described in section 12 of this appendix), unless that pollutant
is specifically excluded (see section 8 of this appendix). The
pollutant with the highest index value for the day is the
``critical'' pollutant, and must be included in the daily AQI
report. As a result, the AQI for any given day is equal to the index
value of the critical pollutant for that day. For the purposes of
reporting the AQI, the indexes for PM10 and
PM2.5 are to be considered separately.
* * * * *

                                                            Table 2--Breakpoints for the AQI
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      These breakpoints                                                            Equal these AQIs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                               PM2.5          PM10
O3 (ppm) 8-  O3 (ppm) 1-    ([micro]g/     ([micro]g/    CO (ppm)    SO2 (ppm)   NO2 (ppm) 1-     AQI                         Category
    hour       hour\1\         m\3\)         m\3\)                                   hour
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.000-0.059  ...........        0.0-15.4         0-54      0.0-4.4  0.000-0.034      0-0.053         0-50  Good.
0.060-0.075  ...........       15.5-40.4       55-154      4.5-9.4  0.035-0.144  0.054-0.100       51-100  Moderate.
0.076-0.095  0.125-0.164       40.5-65.4      155-254     9.5-12.4  0.145-0.224  0.101-0.360      101-150  Unhealthy for Sensitive Groups.
0.096-0.115  0.165-0.204  \3\ 65.5-150.4      255-354    12.5-15.4  0.225-0.304   0.361-0.64      151-200  Unhealthy.
0.116-0.374  0.205-0.404      \3\ 150.5-      355-424    15.5-30.4  0.305-0.604    0.65-1.24      201-300  Very Unhealthy.
                                   250.4
      (\2\)  0.405-0.504      \3\ 250.5-      425-504    30.5-40.4  0.605-0.804    1.25-1.64      301-400  Hazardous.
                                   350.4
      (\2\)  0.505-0.604      \3\ 350.5-      505-604    40.5-50.4  0.805-1.004    1.65-2.04      401-500  Hazardous.
                                   500.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Areas are generally required to report the AQI based on 8-hour ozone values. However, there are a small number of areas where an AQI based on 1-hour
  ozone values would be more precautionary. In these cases, in addition to calculating the 8-hour ozone index value, the 1-hour ozone index value may be
  calculated, and the maximum of the two values reported.
\2\ 8-hours O3 values do not define higher AQI values (>=301). AQI values of 301 or greater are calculated with 1-hour O3 concentrations.
\3\ If a different SHL for PM2.5 is promulgated, these numbers will change accordingly.

[FR Doc. 2010-1990 Filed 2-8-10; 8:45 am]
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