[Federal Register Volume 69, Number 84 (Friday, April 30, 2004)]
[Rules and Regulations]
[Pages 23951-24000]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-9153]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 50, 51 and 81

[OAR 2003-0079, FRL-7651-7]
RIN 2060-AJ99


Final Rule To Implement the 8-Hour Ozone National Ambient Air 
Quality Standard--Phase 1

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: In this document, EPA is taking final action on key elements 
of the program to implement the 8-hour ozone national ambient air 
quality standard (NAAQS or standard). This final rule addresses the 
following topics: classifications for the 8-hour NAAQS; revocation of 
the 1-hour NAAQS (i.e., when the 1-hour NAAQS will no longer apply); 
how anti-backsliding principles will ensure continued progress toward 
attainment of the 8-hour ozone NAAQS; attainment dates; and the timing 
of emissions reductions needed for attainment. We are issuing this rule 
so that States and Tribes will know how we plan to classify areas and 
transition from implementation of the 1-hour NAAQS to implementation of 
the 8-hour NAAQS. The intended effect of the rule is to provide 
certainty to States and Tribes regarding classifications for the 8-hour 
NAAQS and their continued obligations with respect to existing 
requirements. This document is Phase 1 of the program to implement the 
8-hour ozone NAAQS. We plan to issue a second rule, Phase 2, within the 
next several months which will address the remaining 8-hour 
implementation issues, e.g., requirements for reasonable further 
progress (RFP), requirements for modeling and attainment 
demonstrations, and requirements for reasonably available control 
measures (RACM) and reasonably available control technology (RACT).

DATES: Effective Date: This rule is effective on June 15, 2004.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. OAR-2003-0079. All documents in the docket are listed in 
the EDOCKET index at http://www.epa.gov/edocket. Although listed in the 
index, some information is not publicly available, i.e., Confidential 
Business Information or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available either electronically in EDOCKET or in hard copy at the EPA 
Docket Center (Air Docket), EPA/DC, EPA West, Room B102, 1301 
Constitution Ave., NW., Washington, DC. The Public Reading Room is open 
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The telephone number for the Public Reading Room is (202) 
566-1744, and the telephone number for the Office of Air and Radiation 
Docket and Information Center is (202) 566-1742.
    In addition, we have placed a variety of earlier materials 
regarding implementation of the 8-hour ozone NAAQS on the Web site: 
http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr.

FOR FURTHER INFORMATION CONTACT: Mr. John Silvasi, Office of Air 
Quality

[[Page 23952]]

Planning and Standards, U.S. Environmental Protection Agency, Mail Code 
C539-02, Research Triangle Park, NC 27711, phone number (919) 541-5666, 
fax number (919) 541-0824 or by e-mail at [email protected] or Ms. 
Denise Gerth, Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Mail Code C539-02, Research Triangle 
Park, NC 27711, phone number (919) 541-5550, fax number (919) 54l-0824 
or by e-mail at [email protected].

SUPPLEMENTARY INFORMATION:

Outline

I. When Did EPA Propose this Rule?
II. What is EPA's Schedule for Taking Final Action on the Proposal?
III. What is Included in this Rule?
IV. In Short, what does this Final Rule Contain?
    A. How will EPA reconcile the classification provisions of 
subparts 1 and 2? How will EPA classify nonattainment areas for the 
8-hour standard?
    B. How will EPA treat attainment dates for the 8-Hour ozone 
standard?
    C. How will EPA implement the transition from the 1-hour to the 
8-hour standard in a way to ensure continued momentum in States' 
efforts toward cleaner air?
    D. What is the required timeframe for obtaining emissions 
reductions to ensure attainment by the attainment date?
V. EPA's Final Rule.
    A. How will EPA reconcile the classification provisions of 
subparts 1 and 2? How will EPA classify nonattainment areas for the 
8-hour NAAQS?
    1. Background.
    a. Statutory framework and Supreme Court decision.
    b. EPA's proposed rule and notice reopening the comment period.
    2. Summary of final rule
    a. Why did EPA select Option 2?
    (i) Why will Option 2 best accomplish the policy goals of EPA?
    (ii) How is Option 2 Consistent with the CAA as Interpreted by 
the Supreme Court?
    3. Comments and Responses.
    4. Under the final classification approach, how will EPA 
classify subpart 1 areas?
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses.
    5. Will EPA adjust classifications?
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses.
    6. Proposed Incentive Feature.
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses.
    B. How will EPA treat attainment dates for the 8-hour ozone 
NAAQS?
    1. Background.
    2. Summary of final rule.
    3. Comments and Responses.
    4. How Will EPA Address the Provision Regarding 1-Year 
Extensions?
    a. Background.
    b. Summary of final rule.
    c. Comments and Response
    C. How will EPA implement the transition from the 1-hour to the 
8-hour NAAQS in a way to ensure continued momentum in States' 
efforts toward cleaner air?
    1. When will EPA revoke the 1-hour NAAQS?
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses
    2. What requirements that applied in an area for the 1-hour 
NAAQS continue to apply after revocation of the 1-hour NAAQS for 
that area?
    a. Background.
    b. Summary of Final Rule.
    c. Section 51.905(a)(1): 8-Hour NAAQS Nonattainment/1-Hour NAAQS 
Nonattainment
    (i) Mandatory Control Measures.
    (ii) Discretionary control measures.
    (iii) Measures to address growth.
    (iv) Planning SIPs.
    d. Section 51.905(a)(2): 8-Hour NAAQS Nonattainment/1-Hour NAAQS 
Maintenance
    (i) Mandatory Control Measures.
    (ii) Discretionary Control measures.
    (iii) Measures to address growth.
    (iv) Planning SIPs.
    e. Section 51.905(a)(3): 8-Hour NAAQS Attainment /1-Hour NAAQS 
Nonattainment
    (i) Mandatory control obligations.
    (ii) Discretionary control obligations.
    (iii) Measures to address growth.
    (iv) Planning SIPs.
    (v) Maintenance Plans for the 8-hour NAAQS.
    f. Section 51.905(a)(4): 8-Hour NAAQS Attainment/1-Hour NAAQS 
Maintenance
    (i) Obligations in an approved SIP.
    (ii) Maintenance plan.
    3. For how long do these obligations continue to apply?
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses.
    4. Which portions of an area designated for the 8-hour NAAQS 
remain subject to the 1-hour NAAQS obligations?
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses.
    5. What obligations that applied for the 1-hour NAAQS will no 
longer apply after revocation of the 1-hour NAAQS for an area?
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses.
    (i) Comments on June 2, 2003 proposal:
    (ii) Comments on draft regulatory text.
    6. What is the continued applicability of the NOX SIP 
Call after revocation of the 1-hour NAAQS?
    a. Background.
    b. Summary of Final Rule.
    c. Comments and Responses.
    (i) Comments on the June 2, 2003 proposal:
    D. What is the required timeframe for obtaining emissions 
reductions to ensure attainment by the attainment date?
    1. Background.
    2. Summary of final rule.
    3. Comments and Responses
    E. Conformity Under the 8-Hour Ozone Standard
    F. Comments on Other Issues
    1. Designations of nonattainment and attainment areas:
    2. Early Action Compacts (EACs):
    3. Health and environmental concerns:
    4. Clarity and understandability of proposed rule:
    5. Regulatory text:
    6. Requests for Extension of Comment Periods:
    G. Other Considerations
    1. What happens if a source is in the process of PSD permitting 
at the time that the area in which it is located is designated as 
nonattainment for the 8-hour ozone NAAQS?
    H. EPA's Final Action.
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer Advancement Act
    J. Executive Order 12898: Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Congressional Review Act
    L. Petitions for Judicial Review
    M. Determination Under Section 307(d)

I. When Did EPA Propose This Rule?

    On June 2, 2003 (68 FR 32805), we published a proposed rule to 
implement the 8-hour ozone NAAQS. The proposal addressed a number of 
implementation issues, including the two core implementation issues 
addressed in this final rule, e.g., how the Clean Air Act (CAA or Act) 
classification provisions will apply for the 8-hour ozone NAAQS and the 
transition from the 1-hour NAAQS to the 8-hour NAAQS, including when 
the 1-hour NAAQS will be revoked and anti-backsliding principles. We 
proposed one or more options for each issue addressed in the proposal. 
In addition, we included two possible frameworks to implement the 8-
hour ozone NAAQS. These frameworks were complete implementation 
strategies comprised of one option for each implementation issue 
addressed in the proposed rule. The following principles guided us in 
the development of the underlying

[[Page 23953]]

options and the frameworks to implement the 8-hour ozone NAAQS in the 
proposed rule: to protect public health, provide incentives for 
expeditious attainment of the 8-hour ozone NAAQS and avoid incentives 
for delay; to provide reasonable but expeditious attainment deadlines; 
to establish a basic, straightforward structure that could be 
communicated easily; to provide flexibility to States and EPA on 
implementation approaches and control measures while ensuring that the 
implementation strategy is supported by the CAA; to emphasize national 
and regional measures to help areas come into attainment and, where 
possible, reduce the need for those local controls that are more 
expensive than national and regional measures; and to provide a smooth 
transition from implementation of the 1-hour ozone NAAQS to 
implementation of the 8-hour ozone NAAQS. An additional goal was to 
clarify the role of Tribes in implementing the 8-hour ozone NAAQS. 
Section 301(d) of the CAA recognizes that the American Indian Tribal 
governments are generally the appropriate authority to implement the 
CAA in Indian country. As discussed in the Tribal Authority Rule (TAR) 
(63 FR 7262, February 12, 1998, and 59 FR 43960-43961, August 25, 
1994), it is appropriate to treat Tribes in the same manner as States. 
Therefore, when we discuss the role of the State in implementing this 
rule we are also referring to the Tribes. Please refer to the proposed 
rule (68 FR 32802, June 2, 2003) for a detailed discussion and 
background information on the 8-hour ozone problem and EPA's strategy 
for addressing it, the 8-hour ozone NAAQS and associated litigation, 
and the stakeholder process for gathering input into this effort, among 
other topics.
    On August 6, 2002 (68 FR 46536), we published a notice of 
availability of the draft regulatory text for the proposed rule to 
implement the 8-hour ozone NAAQS. This notice started a 30-day public 
comment period on the draft regulatory text. In addition, on October 
21, 2003 (68 FR 60054), we reopened the public comment period for 15 
days to solicit additional comment on alternative approaches for 
classifying ozone nonattainment areas, based on comments received 
during the comment period.

II. What Is EPA's Schedule for Taking Final Action on the Proposal?

    In our June 2, 2003 proposal, we stated that we planned to issue 
the final implementation rule in December of 2003. While there is not a 
CAA deadline for promulgating a strategy to implement the 8-hour ozone 
NAAQS, the CAA does establish a deadline for EPA to promulgate 
designations of nonattainment areas under section 107 of the CAA.\1\ We 
have entered into a consent decree that requires us to promulgate 
designations by April 15, 2004.\2\ Our goal was to issue a final 
implementation rule by the end of 2003 because the States and Tribes 
indicated a strong interest in having an opportunity to understand the 
impacts of being designated nonattainment prior to promulgation of 
designations for the 8-hour NAAQS. Based on the large number of public 
comments received on our proposal and our need to consider and respond 
to those comments before taking final action, we were unable to issue a 
final rule prior to April 15, 2004 that addresses all issues raised in 
the proposal. This final rule addresses several key components of the 
proposed rule: how the classification provisions of the CAA will apply 
for purposes of the 8-hour ozone NAAQS and the transition from the 1-
hour NAAQS to the 8-hour NAAQS, including when the 1-hour NAAQS will be 
revoked, how anti-backsliding principles will ensure continued progress 
toward attainment of the 8-hour ozone NAAQS, attainment dates, and the 
timing of emissions reductions needed for attainment.
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    \1\ Section 107(d) of the CAA sets forth a schedule for 
designations following the promulgation of a new or revised NAAQS. 
The Transportation Equity Act for the Twenty-first Century (TEA-21) 
revised the deadline to promulgate nonattainment designations to 
provide an additional year (to July 2000) but HR3645 (EPA's 
appropriation bill in 2000) restricted EPA's authority to spend 
money to designate areas until June 2001 or the date of the Supreme 
Court ruling in the litigation challenging the NAAQS, whichever came 
first.
    \2\ American Lung Association v. EPA (D.D.C. No. 1:02CV02239).
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    Within the next several months, we plan to issue a second final 
rule, Phase 2, which will address many of the planning and control 
obligations under sections 172 and 182 of the CAA that will apply for 
purposes of implementing the 8-hour ozone NAAQS. These include, among 
other things, RFP, RACT, attainment demonstrations and maintenance 
plans, and new source review (NSR). Neither Phase 1 nor Phase 2 will 
address the appropriate tests under the 8-hour ozone NAAQS for 
demonstrating conformity of Federal actions to State implementation 
plans (SIPs). A proposed rule was published on November 5, 2003 (68 FR 
62689) addressing transportation conformity requirements applicable in 
8-hour ozone nonattainment areas. In addition, EPA is revising its 
general conformity regulations and plans to issue a proposed rule in 
the spring of 2004.

III. What Is Included in This Rule?

    Today's action, Phase 1 of the implementation rule, focuses on two 
key implementation issues: (1) Classifying areas for the 8-hour NAAQS 
and (2) transitioning from the 1-hour to the 8-hour NAAQS, which 
includes revocation of the 1-hour NAAQS and the anti-backsliding 
principles that should apply upon revocation.\3\ In addition, it 
addresses several additional, related issues. We believe that 
classifications and anti-backsliding are key elements of the 
implementation program that are of primary interest to the States and 
Tribes prior to the final designations. In addition, because section 
182(a) of the CAA provides that classifications will occur ``by 
operation of law'' at the time of designation, EPA believes it is 
critical that the public understands at the time of designations how 
the classification provisions will apply.
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    \3\ We use the term ``revocation'' as shorthand for a 
determination under 40 CFR 50.9(b) that the 1-hour NAAQS no longer 
applies to one or more areas.
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IV. In Short, What Does This Final Rule Contain?

    This summary is intended to give only a convenient overview of our 
final rule. It should not be relied on for the details of the actual 
rule. The final rule (regulatory text) and the discussion of it in the 
next section below should be consulted directly.
    Both the preamble and the rule may use the following terms to 
discuss four categories of areas for purposes of the anti-backsliding 
provisions: (1) 8-hour NAAQS Nonattainment/1-hour NAAQS Nonattainment; 
(2) 8-hour NAAQS Nonattainment/1-hour NAAQS Maintenance; (3) 8-hour 
NAAQS Attainment/1-hour NAAQS Nonattainment; (4) 8-hour NAAQS 
Attainment/1-hour NAAQS Maintenance. These categories are, 
respectively: (1) Areas that remain designated nonattainment for the 1-
hour NAAQS at the time of designation as nonattainment for the 8-hour 
NAAQS; (2) Areas that are maintenance areas for the 1-hour NAAQS at the 
time of designation as nonattainment for the 8-hour NAAQS; (3) Areas 
that remain designated nonattainment for the 1-hour NAAQS at the time 
of designation as attainment for the 8-hour NAAQS; and (4) Areas that 
are maintenance areas for the 1-hour NAAQS at the time of designation 
as attainment for the 8-hour NAAQS.

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A. How Will EPA Reconcile the Classification Provisions of Subparts 1 
and 2? How Will EPA Classify Nonattainment Areas for the 8-Hour 
Standard?

    The final rule incorporates Option 2 of the proposal. Each area 
with a current 1-hour design value at or above 0.121 ppm (the lowest 1-
hour design value in Table 1 of subpart 2) will be classified under 
subpart 2 based on its 8-hour design value. All other areas will be 
covered under subpart 1 using their 8-hour design values.
    In brief, this approach works as follows:
     First, we will determine which 8-hour areas will 
be covered under subpart 2 and which under subpart 1. Any area with a 
1-hour ozone design value (at the time of designation) that meets or 
exceeds the statutory level of 0.121 ppm that Congress specified in 
Table 1 of section 181 will be classified under subpart 2 and will be 
subject to the control obligations associated with its 
classification.\4\ Any area with a 1-hour design value (at the time of 
designation) that is below the level of 0.121 ppm will be covered under 
subpart 1 and subject to the control obligations in section 172.
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    \4\ In the Phase 2 rule, we will address the control obligations 
that apply to areas under both subpart 1 and subpart 2.
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     Second, subpart 2 areas will be classified as 
marginal, moderate, serious, severe or extreme based on the area's 8-
hour design value (at the time of designation). Since Table 1 is based 
on 1-hour design values, and application of the Table as written would 
produce absurd results, we are promulgating a regulation translating 
the thresholds in Table 1 of section 181 from 1-hour values to 8-hour 
values.
Under the Final Classification Approach, How Will EPA Classify Subpart 
1 Areas?
    We are adopting the second option but modified as a result of 
comments. We are creating an overwhelming transport classification that 
will be available to subpart 1 areas that demonstrate they are affected 
by overwhelming transport of ozone and its precursors and demonstrate 
they meet the definition of a rural transport area in section 182(h). 
However, areas would not have to demonstrate that transport was due 
solely to sources from outside the State (interstate transport) as was 
implied by the June 2, 2003 proposal. All other areas that do not 
qualify for the overwhelming transport classification would not be 
classified.
Proposed Incentive Feature
    We are not including the proposed incentive feature in the final 
rule.

B. How Will EPA Treat Attainment Dates for the 8-Hour Ozone Standard?

    We are adopting the time periods for attainment that we proposed 
for areas under both subpart 1 and subpart 2 of the CAA. For areas 
subject to subpart 2 of the CAA, the maximum period for attainment will 
run from the effective date of designations and classifications for the 
8-hour standard and will be the same periods as provided in Table 1 of 
section 181(a):

 Marginal--3 years
 Moderate--6 years
 Serious--9 years
 Severe--15 or 17 years
 Extreme--20 years
    Consistent with section 172(a)(2)(A), for areas subject to subpart 
1 of the CAA, the period for attainment will be no later than 5 years 
after the effective date of the designation. However, EPA may grant an 
area an attainment date no later than 10 years after designation, if 
warranted based on the factors provided in section 172(a)(2)(A).
How Will EPA Address the Provision Regarding 1-Year Extensions?
    We are adopting the interpretation that we proposed on June 2, 
2003. Under both sections 172(a)(2)(C) and 181(a)(5), an area will be 
eligible for the first of the 1-year extensions under the 8-hour 
standard if, for the attainment year, the area's 4th highest daily 8-
hour average is 0.084 ppm or less. The area will be eligible for the 
second extension if the area's 4th highest daily 8-hour value, averaged 
over both the original attainment year and the first extension year, is 
0.084 ppm or less.

C. How Will EPA Implement the Transition From the 1-Hour to the 8-Hour 
Standard in a Way To Ensure Continued Momentum in States' Efforts 
Toward Cleaner Air?

    There are two key issues that EPA considered together regarding the 
transition from the 1-hour standard to the 8-hour standard: (1) When 
will the 1-hour standard no longer apply (i.e., be ``revoked''); and 
(2) what protections are in place to ensure that, once the 1-hour 
standard is revoked, air quality will not degrade and that progress 
toward attainment will continue as areas transition from implementing 
the 1-hour standard to implementing the 8-hour standard. As in the 
proposed rule, the second key issue has three components: (1) What 
requirements that applied based on an area's classification for the 1-
hour standard must continue to apply to that area; (2) for how long; 
and (3) in what area. Below, we set forth our final transition approach 
in four parts: (1) When will the 1-hour standard no longer apply (i.e., 
when will it be revoked); (2) what 1-hour obligations should continue 
to apply once the 1-hour standard is revoked; (3) how long should those 
requirements continue to apply; and (4) what is the geographic area 
subject to the requirement.
1. When Will EPA Revoke the 1-Hour Standard?
    We are adopting Option 1. We will revoke the 1-hour standard in 
full, including the associated designations and classifications, 1 year 
following the effective date of the designations for the 8-hour NAAQS.
2. What Requirements That Applied in an Area for the 1-Hour NAAQS 
Continue To Apply After Revocation of the 1-Hour NAAQS for That Area?
    The approach we are adopting in the final rule is summarized below 
under the individual sections discussing each category of area and type 
of control obligation.
    a. Section 51.905(a)(1): 8-Hour NAAQS Nonattainment/1-Hour NAAQS 
Nonattainment
    (i) Mandatory control measures. We are adopting the approach we 
proposed. All areas designated nonattainment for the 8-hour ozone NAAQS 
and designated nonattainment for the 1-hour ozone NAAQS at the time of 
designation for the 8-hour NAAQS remain subject to control measures 
that applied by virtue of the area's classification for the 1-hour 
standard.
    (ii) Discretionary control measures. We are adopting the approach 
we set forth in our proposed rule. A State may revise or remove 
discretionary control measures (including enforceable commitments) 
contained in its SIP for the 1-hour standard so long as the State 
demonstrates consistent with section 110(l) that such removal or 
modification will not interfere with attainment of or progress toward 
the 8-hour ozone NAAQS (or any other applicable requirement of the 
CAA).
    (iii) Measures to address growth. We are not adopting the approach 
set forth in our proposed rule. For areas designated nonattainment for 
the 1-hour NAAQS at the time of designation for the 8-hour NAAQS and 
that are designated nonattainment for the 8-hour NAAQS, the major 
source applicability cut-offs and offset ratios for the area's 1-hour 
classification would not continue to apply after revocation of the 1-
hour NAAQS.

[[Page 23955]]

    (iv) Planning SIPs.
    (A) Outstanding rate of progress (ROP) Obligation. We are adopting 
the approach set forth in our proposed rule for this category of areas. 
States remain obligated to meet the CAA-mandated ROP emission reduction 
targets that applied for the 1-hour standard, but discretionary 
measures adopted to meet those targets may be modified, if the State 
makes the necessary showing under section 110(l).
    (B) Unmet attainment demonstration obligations. In the final rule, 
we are allowing the States to choose among three options that are 
tailored after the approaches addressed in the proposed rule. Thus, 
rather than establishing one mandatory approach, we are adopting a rule 
that will allow States to choose any one of the following three 
options:
     Option 1. Submit a 1-hour attainment 
demonstration.
     Option 2. Submit, no later than 1 year after the 
effective date of the 8-hour designations, an early five percent 
increment of progress plan toward the 8-hour standard.
     Option 3. Submit an early 8-hour ozone 
attainment demonstration SIP that ensures that the first segment of RFP 
is achieved early.
    b. Section 51.905(a)(2): 8-Hour NAAQS Nonattainment/1-Hour NAAQS 
Maintenance
    (i) Mandatory control measures. We are adopting the approach we 
took in the proposal and the draft regulatory text. This category of 
areas must continue to implement mandatory control requirements (i.e., 
``applicable requirements'') that have been approved into the SIP. 
However, since maintenance areas do not have any outstanding obligation 
to adopt mandatory control obligations for the 1-hour standard, the 
provision only addresses implementation, not adoption. In addition, 
this section recognizes that maintenance areas had the flexibility to 
move mandatory controls to the contingency measures portion of their 
maintenance plan.
    (ii) Discretionary control measures. As with discretionary control 
measures for 8-hour NAAQS nonattainment/1-hour NAAQS nonattainment 
areas, 1-hour NAAQS nonattainment/1-hour NAAQS maintenance areas will 
retain the discretion to modify any discretionary control measures upon 
a demonstration under section 110(l). We are not promulgating 
regulatory text because sections 110(l) and 193 of the CAA govern such 
SIP revisions.
    (iii) Measures to address growth. We are adopting the approach we 
proposed, but our rationale relies on the final rule's provision that 
NSR under the 1-hour standard will no longer be a required 
implementation plan element as of revocation of the 1-hour standard. If 
an area has been redesignated to attainment for the 1-hour standard as 
of the effective date of the 8-hour nonattainment designation and is no 
longer required to implement a nonattainment NSR program, the area will 
not be required to revert back to the program it had for purposes of 
the 1-hour ozone standard.
    As noted elsewhere, NSR offset ratios and major stationary source 
applicability provisions under the 1-hour standard are not being 
defined as ``applicable requirements'' after the 1-hour standard is 
revoked.
    (iv) Planning SIPs. We are adopting the approach taken in the draft 
regulatory text. In redesignating an area to attainment, EPA must 
conclude that the area has met all requirements applicable under 
section 110 and part D. Thus, maintenance areas do not have continuing 
progress and attainment demonstration requirements.
    c. Section 51.905(a)(3): 8-Hour NAAQS Attainment/1-Hour NAAQS 
Nonattainment
    (i) Mandatory control obligations. We are adopting an approach 
consistent with our proposed rule. We have determined that mandatory 
control obligations will no longer apply once an area attains the 8-
hour standard. Thus, because these areas are attaining the 8-hour 
standard, the State may request that obligations under applicable 
requirements be shifted to contingency measures once the 1-hour 
standard is revoked, consistent with sections 110(l) and 193 of the 
CAA. However, the State cannot remove the obligations from the SIP.
    (ii) Discretionary control obligations. 8-hour NAAQS attainment/1-
hour NAAQS nonattainment areas will retain the discretion to modify any 
discretionary controls upon a demonstration under section 110(l). 
However, such controls must remain in the SIP as contingency measures.
    (iii) Measures to address growth. We are adopting the approach we 
set forth in our proposed rule for this category of areas. After the 1-
hour standard is revoked, the CAA requires such areas to comply with 
prevention of significant deterioration (PSD), not NSR.
    (iv) Planning SIPs. We are adopting our proposal with some 
modification. An area of this category will not be required to develop 
and submit outstanding attainment demonstration and ROP plans for the 
1-hour standard for so long as the area continues to maintain the 8-
hour NAAQS. However, if the area violates the 8-hour NAAQS prior to 
having an approved 8-hour maintenance plan under section 110(a)(1), the 
area will be required to submit a SIP revision to address outstanding 
ROP and attainment demonstration plans.
    (v) Maintenance plans for the 8-hour NAAQS. We are adopting the 
approach we proposed. Areas that are either 8-hour NAAQS attainment/1-
hour NAAQS nonattainment or 8-hour NAAQS attainment /1-hour NAAQS 
maintenance must adopt and submit a maintenance plan consistent with 
section 110(a)(1) within 3 years of designation as attainment for the 
8-hour NAAQS. The maintenance plan should provide for continued 
maintenance of the 8-hour standard for 10 years following designation 
for the 8-hour NAAQS and should include contingency measures.
    d. Section 51.905(a)(4): 8-Hour NAAQS Attainment/1-Hour NAAQS 
Maintenance
    In the final rule, we created a section 51.905(a)(4) to apply to 
this category of areas. It covers obligations in an approved SIP and 
maintenance plans similar in manner to areas that are attainment for 
the 8-hour standard and were attainment for the 1-hour standard and had 
a maintenance plan.
3. For How Long Do These Obligations Continue To Apply?
    We are adopting Option 2--control obligations an area is required 
to retain in the approved SIP for an area's 1-hour classification must 
continue to be implemented under the SIP until the area attains and is 
redesignated to attainment for the 8-hour NAAQS. At that time, the 
State may relegate such controls to the contingency measure portion of 
the SIP if the State demonstrates in accordance with section 110(l) 
that doing so will not interfere with maintenance of the 8-hour NAAQS 
or any other applicable requirement of the CAA. If at the time the area 
is redesignated to attainment for the 8-hour standard the State has an 
outstanding obligation to adopt a control requirement under the 1-hour 
standard, it remains obligated to do so, but may adopt it as a 
contingency measure.
4. Which Portions of an Area Designated for the 8-Hour NAAQS Remain 
Subject to the 1-Hour NAAQS Obligations?
    The final rule incorporates most aspects of the approach as that 
contained in the proposal and in the draft regulatory text. The final 
rule provides that only the portion of the designated area for the 8-
hour NAAQS that was designated nonattainment for

[[Page 23956]]

the 1-hour NAAQS is required to comply with the planning obligations, 
except in one circumstance: if the State elects to provide an early 
increment of progress or an early 8-hour attainment demonstration in 
lieu of an outstanding 1-hour attainment demonstration (for an 8-hour 
NAAQS nonattainment/1-hour NAAQS nonattainment area under 
51.905(a)(1)(ii)(B) and (C)), the increment of progress or early 8-hour 
attainment plan must apply for purposes of the entire 8-hour 
nonattainment area.
    The final rule does not follow the approach in the proposal for the 
maintenance plan requirement for 8-hour attainment areas. The 
maintenance plans required for these areas must demonstrate maintenance 
only for the area designated nonattainment for the 1-hour NAAQS at the 
time of designation of the 8-hour standard.
5. What Obligations That Applied for the 1-hour NAAQS Will No Longer 
Apply After Revocation of the 1-hour NAAQS for an Area?
    We are revising the approach we set forth in our proposed rule. In 
addition to the obligations noted in our proposal that would no longer 
apply after the 1-hour NAAQS is revoked, we are also providing 
clarification regarding the penalty obligations under sections 
181(b)(4) and 185 of the CAA that apply in severe and extreme areas 
that do not attain the 1-hour standard by the applicable attainment 
date. The final rule also would not retain NSR under the 1-hour NAAQS. 
The final rule provides that as of the effective date of revocation of 
the 1-hour standard:
     We will no longer make findings of failure to 
attain the 1-hour standard and, therefore, (a) we will not reclassify 
areas to a higher classification for the 1-hour standard based on such 
a finding, and (b) areas that were classified as severe or extreme for 
the 1-hour NAAQS are not obligated to impose fees as provided under 
sections 181(b)(4) and 185 of the CAA under the 1-hour standard.
     Areas will not be obligated to continue to 
demonstrate conformity for the 1-hour NAAQS as of the effective date of 
the revocation of the 1-hour NAAQS.
     An area with an approved 1-hour maintenance plan 
under section 175A of the CAA may modify the maintenance plan to remove 
obligations related to developing a second 10-year maintenance plan for 
the 1-hour NAAQS and the obligation to implement contingency measures 
upon a violation of the 1-hour NAAQS.
     NSR under the 1-hour NAAQS will no longer be a 
required implementation plan element in areas that are 8-Hour NAAQS 
nonattainment/1-Hour NAAQS nonattainment. Instead, NSR under the 8-hour 
NAAQS will apply.
6. What Is the Continued Applicability of the NOX SIP Call 
After Revocation of the 1-hour NAAQS?
    We are adopting the approach we set forth in our proposed rule and 
draft regulatory text. States must continue to adhere to the emission 
budgets established by the NOX transport rules after the 1-
hour standard is revoked. States retain the authority to revise control 
obligations they have established for specific sources or source 
categories under the NOX SIP Call rule so long as the State 
demonstrates consistent with section 110(l) that such modification will 
not interfere with attainment of or progress toward meeting the 8-hour 
NAAQS or any other applicable requirement of the CAA.

D. What Is the Required Timeframe for Obtaining Emissions Reductions to 
Ensure Attainment by the Attainment Date?

    We are adopting the approach we set forth in our proposed rule, 
namely that emissions reductions needed for attainment must be 
implemented by the beginning of the ozone season immediately preceding 
the area's attainment date.

V. EPA's Final Rule

A. How Will EPA Reconcile the Classification Provisions of Subparts 1 
and 2? How Will EPA Classify Nonattainment Areas for the 8-hour NAAQS? 
(Section VI.A. of Proposal; See 68 FR 32811; Section 51.902 of Draft 
and Final Rules)

1. Background
    a. Statutory framework and Supreme Court decision. The CAA contains 
two sets of requirements--subpart 1 and subpart 2--that establish 
requirements for State plans implementing the ozone NAAQS in 
nonattainment areas. (Both are found in title I, part D.) Subpart 1 
contains general, less prescriptive, requirements for SIPs for 
nonattainment areas for any pollutant--including ozone--governed by a 
NAAQS. Subpart 2 provides more specific requirements for ozone 
nonattainment SIPs.\5\
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    \5\ State Implementation Plans; General Preamble for the 
Implementation of Title of the CAA Amendments of 1990; Proposed 
Rule.'' April 16, 1992 (57 FR 13498 at 13501 and 13510).
---------------------------------------------------------------------------

    When we promulgated the 8-hour ozone NAAQS on July 18, 1997, we 
indicated that we anticipated that States would implement the 8-hour 
NAAQS under the less prescriptive subpart 1 requirements. More 
specifically, we concluded that the CAA required areas designated 
nonattainment for the 1-hour ozone NAAQS to remain subject to the 
subpart 2 requirements for purposes of the 1-hour NAAQS until such time 
as they met that NAAQS (62 FR 38872). We also stated that those areas 
and all other areas would be subject only to subpart 1 for purposes of 
planning for the 8-hour ozone NAAQS. We determined not to immediately 
revoke the 1-hour NAAQS for all areas but to promulgate a rule (40 CFR 
50.9(b)) providing that the 1-hour NAAQS and the associated designation 
would no longer apply to an area once EPA determined the area had 
attained the 1-hour NAAQS. Thus, areas that had not yet attained the 1-
hour NAAQS retained their designation for that NAAQS and remained 
subject to the control obligations associated with their classification 
for the 1-hour NAAQS until they met it.
    In February 2001, the Supreme Court ruled that the statute was 
ambiguous as to the relationship of subparts 1 and 2 for purposes of 
implementing the 8-hour NAAQS. Whitman v. American Trucking 
Associations, 531 U.S. 457, 481-86 (2001). The Court concluded, 
however, that the implementation approach set forth in the final NAAQS 
rule, which provided no role for subpart 2 in implementing the 8-hour 
NAAQS, was unreasonable. Id. Specifically, with respect to classifying 
areas, the Supreme Court stated: [D]oes subpart 2 provide for 
classifying nonattainment ozone areas under the revised standard? It 
unquestionably does.'' Whitman, 531 U.S. at 482.
    Despite recognizing that the classification provisions of subpart 2 
(section 181(a)) apply for purposes of the 8-hour NAAQS, the Supreme 
Court also recognized that the subpart 2 classification scheme does not 
entirely fit with the revised 8-hour NAAQS and left it to EPA to 
develop a reasonable resolution of the roles of subparts 1 and 2 in 
classifying areas for and implementing a revised ozone NAAQS. Id. at 
482-486.
    In particular, the Court noted three portions of section 181--the 
classification provision in subpart 2--that it indicated were ``ill-
fitted to implementation of the revised standard.'' Id. at 483.
     First, the Court recognized that ``using the old 
1-hour averages of ozone levels * * * as subpart 2 requires * * * would 
produce at best an inexact estimate of the new 8-hour averages * * *'' 
Id.

[[Page 23957]]

     Second, the Court recognized that the design 
values in Table 1 is based on the level of the 1-hour NAAQS (0.12 ppm) 
and noted that ``to the extent the new ozone standard is stricter than 
the old one, * * * the classification system of Subpart 2 contains a 
gap, because it fails to classify areas whose ozone levels are greater 
than the new standard (and thus nonattaining) but less than the 
approximation of the old standard codified by Table 1.'' Id.
     Third, the Court recognized that ``Subpart 2's 
method for calculating attainment dates--which is simply to count 
forward a certain number of years from November 15, 1990 * * * seems to 
make no sense for areas that are first classified under a new standard 
after November 15, 1990.'' More specifically, the Court recognized that 
attainment dates for marginal (1993), moderate (1996), and serious 
(1999) areas had passed. Id. at 483-484.
    b. EPA's proposed rule and notice reopening the comment period. In 
light of the Supreme Court's ruling, we examined the statute to 
determine the manner in which the subpart 2 classifications should 
apply for purposes of the 8-hour ozone NAAQS. We paid particular 
attention to the three portions of section 181 that the Supreme Court 
noted were ill-fitted for implementation of the revised 8-hour NAAQS. 
We examined those provisions in light of the legislative history and 
the overall structure of the CAA to determine what Congress intended 
for purposes of implementing a revised, more stringent ozone NAAQS.
    On June 2, 2003 (68 FR 32802), we issued a proposed rule which 
identified two options for classifying areas for the 8-hour ozone 
NAAQS. Under Option 1 (68 FR 32812), we proposed to classify 8-hour 
ozone nonattainment areas according to the severity of their ozone 
pollution based on 8-hour design values.\6\ Because the subpart 2 
classification table is based on 1-hour design values, we proposed to 
translate the classification thresholds in Table 1 of section 181 to 8-
hour design values. Under this option, all 8-hour nonattainment areas 
would be classified under subpart 2 as marginal, moderate, serious, 
severe or extreme.
---------------------------------------------------------------------------

    \6\ The design value of an area is based on the monitor for the 
area recording the highest ozone levels and indicates whether the 
area is violating or meeting the ozone NAAQS. For the 1-hour ozone 
NAAQS, the design value for an area is generally the 4th highest 
monitored ozone level at the monitor over a 3-year period. See 40 
CFR part 50, appendix H and Memorandum of June 18, 1990 from William 
G. Laxton re ``Ozone and Carbon Monoxide Design Value 
Calculations.'' Available at http://www.epa.gov/ttn/naaqs/ozone/ozonetech/laxton.htm. For the 8-hour ozone NAAQS, the design value 
is the average of each yearly 4th highest reading at a monitor over 
a 3-year period. See 40 CFR part 50, appendix I.
---------------------------------------------------------------------------

    Under Option 1, the threshold for the marginal classification would 
be an 8-hour design value of 0.085 ppm. Each of the 8-hour 
classification thresholds would be the same percentage above the 8-hour 
NAAQS as the corresponding statutory 1-hour threshold is above the 1-
hour NAAQS. For example, since the statutory 1-hour ozone level for the 
moderate classification is 15 percent above the 1-hour NAAQS, the 8-
hour ozone level for the moderate classification would be 15 percent 
above the 8-hour NAAQS.
    The EPA developed a second option designed to provide States with 
greater flexibility on the measures included in their plans for meeting 
the 8-hour NAAQS. Under Option 2 (68 FR 32812), which we indicated was 
our preferred option, we proposed a two-step system for determining 
classifications for areas. We proposed as a first step, to divide areas 
into two groups based on each area's current 1-hour ozone design value. 
In accordance with the portion of the Supreme Court decision which 
indicated that there was no gap in the statute for those areas with a 
1-hour design value above 0.121 ppm--the lowest level in Table 1 in 
section 181(a)--we proposed that areas with a current (i.e., determined 
at the time of designation) 1-hour ozone design value greater than or 
equal to 0.121 ppm would be classified under subpart 2 for the 8-hour 
NAAQS. For areas with a 1-hour design value less than 0.121 ppm, i.e., 
those areas the Court stated fell into the gap, we concluded that we 
must make a reasonable determination whether they should be covered 
under subpart 1 or subpart 2. We proposed that all of these areas would 
be covered under subpart 1. For the areas that did not fall into the 
gap and which must be classified under subpart 2, we proposed to 
classify them based on our translation of Table 1 in section 181(a), as 
described under Option 1.
    We received a large number of comments on the classification 
options that we proposed, including recommendations for other 
approaches, most of which were variations on the options we proposed. 
On October 21, 2003 (68 FR 60054), we reopened the comment period on 
the proposed rule for 15 days to provide the public with an opportunity 
for additional comment on alternative approaches for classifying areas 
for the 8-hour ozone NAAQS that were suggested during the comment 
period. We also included two alternative strategies (Alternatives A and 
B) for classifying areas that EPA developed by combining ideas 
suggested by different commenters during the initial comment period.\7\
---------------------------------------------------------------------------

    \7\ The notice also solicited comment on additional issues that 
would arise if we selected one of the approaches identified in the 
notice reopening the comment period: (1) Whether we should modify 
the 5 percent reclassification feature of section 181(a)(4) of the 
CAA if we change our classification scheme to have a narrower range 
for each classification; (2) whether we should adopt the suggestion 
by commenters on the June 2, 2003 proposal that we change the 1-hour 
ozone threshold to 0.125 ppm rather than 0.121 ppm to determine if 
an area falls into subpart 1 vs. subpart 2 under classification 
Option 2; and (3) whether an adjustment other than 50 percent would 
be more appropriate for narrowing the range of each classification.
---------------------------------------------------------------------------

    Alternatives A and B were designed to place more areas in higher 
classifications, which would provide areas with more time to attain but 
would impose additional mandatory control requirements. These 
alternatives also were designed to avoid or reduce instances in which a 
subpart 1 area could have higher 8-hour ozone levels than a subpart 2 
area.
    Alternative A would classify areas solely on the basis of 8-hour 
design values. The key feature of this alternative was that EPA would 
create a classification table of 8-hour values starting from an 8-hour 
design value that, to the extent possible, would be approximately 
equivalent to the 1-hour design value of 0.121 ppm in Table 1. Thus, 
the lowest level in the regulatory table was the 8-hour approximation 
of the 1-hour NAAQS as suggested by commenters, i.e., 0.091 ppm. Areas 
with an 8-hour design value less than 0.091 ppm would be covered under 
subpart 1. Areas with an 8-hour design value at or above this level 
would be classified under subpart 2. To place areas in higher 
classifications, we narrowed the range for each classification to use 
50 percent (instead of 100 percent) of the percentages that the 
classification thresholds were above the 1-hour NAAQS in our proposed 
June 2003 translation of Table 1. In other words, since the moderate 
threshold for the 1-hour NAAQS is 15 percent above the 1-hour NAAQS, we 
would adjust the moderate threshold for purposes of the 8-hour NAAQS to 
be 7.5 percent above 0.091 ppm (the lowest level in Table 1 for 
Alternative A).
    Alternative B, a modified version of Option 2, retained the first 
step of Option 2, where we divide the areas based on their current 1-
hour design value. As in Option 2, areas with 1-hour design values 
exceeding the statutory 0.121 ppm level would be regulated under 
subpart 2. In addition, any ``gap'' area (i.e., those with a 1-hour 
design value less than 0.121 ppm) with a moderate-level (or higher) 
design value would be classified under subpart 2. All

[[Page 23958]]

other gap areas would be covered by subpart 1. As with Alternative A, 
to place subpart 2 areas in higher classifications, we narrowed the 
range for each classification to 50 percent of the range in Table 1 of 
section 181. In other words, the moderate threshold would be 7.5 
percent above the 8-hour NAAQS (0.085 ppm).
2. Summary of Final Rule
    After considering all of the comments that were submitted, we are 
adopting Option 2. Each area with a current 1-hour design value at or 
above 0.121 ppm (the lowest 1-hour design value in Table 1 of subpart 
2) will be classified under subpart 2 based on its 8-hour design value. 
All other areas will be covered under subpart 1 using their 8-hour 
design values.
    In brief, this approach works as follows:
     First, we will determine which 8-hour areas will 
be covered under subpart 2 and which under subpart 1. Any area with a 
1-hour ozone design value (at the time of designation) that meets or 
exceeds the statutory level of 0.121 ppm that Congress specified in 
Table 1 of section 181 will be classified under subpart 2 and will be 
subject to the control obligations associated with its 
classification.\8\ Any area with a 1-hour design value (at the time of 
designation) that is below the level of 0.121 ppm will be covered under 
subpart 1 and subject to the control obligations in section 172.
---------------------------------------------------------------------------

    \8\ In the Phase 2 rule, we will address the control and 
planning obligations that apply to areas under both subpart 1 and 
subpart 2.
---------------------------------------------------------------------------

     Second, subpart 2 areas will be classified as 
marginal, moderate, serious, severe or extreme based on the area's 8-
hour design value (at the time of designation). Since Table 1 of 
section 181 is based on 1-hour design values, and application of the 
Table as written would produce absurd results, we are promulgating a 
regulation translating the thresholds in Table 1 of section 181 from 1-
hour values to 8-hour values. (See Table 1 ``Classification for 8-Hour 
NAAQS for Areas Subject to Section 51.902(a)'' in section 51.903.)
     Third, in accordance with section 181(a)(4) and 
181(b)(3), the State may request a lower or higher classification.
     Finally, as described in more detail below, 
section 172(a)(1) provides EPA with discretion whether to classify 
areas under subpart 1 and we are creating one classification--for 
qualifying areas affected by overwhelming transport. All other areas 
covered under subpart 1 will not be classified.
    a. Why did EPA select Option 2? The EPA carefully considered the 
many comments we received on classification options and, in fact, 
sought additional input on alternatives presented and developed 
pursuant to comments received on the June 2003 proposal. The commenters 
were deeply divided on the merits of the options. Even after the 
conclusion of the October 2003 comment period, most commenters still 
favored Option 2 or Option 1. Only a few favored either Alternative A 
or Alternative B. Those commenters who suggested alternatives to Option 
1 or Option 2 during the initial 60-day comment period did not support 
Alternatives A and B (which blended several suggestions from the 
initial comments) and they remained convinced that their suggested 
approach was the best classification approach.
    Because the commenters were strongly divided over the appropriate 
classification approach, EPA re-examined the various alternatives in 
light of their consistency with the CAA, as interpreted by the Supreme 
Court, and their consistency with EPA's stated goals. While EPA 
believes that Options 1 and 2 and Alternatives A and B are all legally 
supportable under the CAA, we concluded that Option 2 best fits with 
the policy goals enunciated by EPA in the proposal and re-affirmed 
here. Thus, EPA has selected Option 2. We explain below why Option 2 
will best accomplish the policy goals of EPA and why we believe it is 
consistent with the CAA.
    (i) Why will Option 2 best accomplish the policy goals of EPA? One 
of EPA's stated goals at proposal was to provide flexibility to States 
and Tribes on implementation approaches and control measures within the 
structure of the CAA. As compared with the other alternatives 
considered, Option 2 places more areas under the more flexible 
provisions of the CAA (subpart 1), which will provide the States and 
Tribes with greater discretion in determining the mix of controls 
needed to expeditiously attain the 8-hour NAAQS. For example, Option 1 
would place all areas under subpart 2, which mandates a number of 
specific control measures, thus limiting the States and Tribes ability 
to consider whether there are more effective and less costly ways to 
achieve the same level of emission reductions.\9\ For example, an area 
might be able to achieve greater air quality improvement at less cost 
from local NOX reductions than from local volatile organic 
compounds (VOC) reductions of 15 percent mandated for certain subpart 2 
areas. This will enable some areas to meet the 8-hour NAAQS at less 
cost than under the other classification options because the States and 
Tribes will have greater flexibility in determining which control 
requirements to adopt to meet the NAAQS. Because areas are required to 
attain the NAAQS as expeditiously as practicable under both subpart 1 
and subpart 2, Option 2 should not result in longer attainment periods 
than Option 1, with the exception of areas significantly affected by 
transported pollution (discussed below).
---------------------------------------------------------------------------

    \9\ Similarly, Alternatives A and B would result in fewer areas 
being placed under subpart 1. (See 68 FR 60060, Table 2. October 21, 
2003).
---------------------------------------------------------------------------

    Additionally, placing some areas in subpart 1 provides States and 
EPA with greater flexibility to determine appropriate controls for 
areas that would have difficulty attaining the 8-hour NAAQS due to 
interstate pollution transport. In the 13 years since the CAA 
Amendments of 1990 were enacted (at which time, Congress created 
subpart 2), we have learned much about the long-range transport of 
ozone and the importance of employing regional controls in addition to 
local controls. Subpart 2 does not allow EPA and the States to consider 
transported pollution in determining the feasibility and benefits of 
mandated controls or in determining the appropriate attainment date for 
an area. Because of our increased understanding of transported 
pollution since Congress enacted the more restrictive provisions of 
subpart 2, we believe it makes sense to adopt an approach that does not 
shift ``gap'' areas into subpart 2. In other words, where Congress has 
not explicitly mandated that areas are subject to subpart 2, we don't 
believe it makes sense to adopt an approach that would shift some or 
all of those ``gap'' areas to subpart 2, which provides significantly 
less flexibility for bringing areas affected by transported pollution 
into attainment. (We discuss in more detail the flexibility provided by 
subpart 1 and how it better allows consideration of the current 
scientific knowledge regarding ozone formation and transport in the 
section below discussing why we place all of the ``gap'' areas in 
subpart 1.)
    The EPA recognizes that the flexibility of Option 2 comes with some 
added complexity. One of EPA's stated goals was to establish an 
approach that is easy to understand. While Option 1 (classifying all 
areas under subpart 2) is simpler, we believe our goals regarding 
flexibility outweigh the simplicity of Option 1.
    Another of EPA's stated aims at proposal was to ensure expeditious 
but reasonable attainment dates for the 8-hour NAAQS. The EPA believes 
that Option 2 is consistent with this

[[Page 23959]]

principle. Compared to Alternatives A and B, Option 2 will place more 
areas in lower classifications with shorter maximum attainment dates, 
encouraging expeditious attainment. While some commenters believed that 
maximum attainment dates under Option 2 would not allow enough time for 
some areas to meet the NAAQS, we believe that Option 2 provides 
sufficient time for most areas and that to the extent some areas may 
have difficulty, the CAA provides an avenue for relief, which is 
discussed below.
    Based on information concerning the hypothetical nonattainment 
areas,\10\ \11\ we are confident that under Option 2 most areas 
currently exceeding the 8-hour NAAQS will be able to meet the NAAQS 
within the time limits provided for their classification, taking into 
consideration projected improvements in air quality under current 
programs and the potential for adoption of further national, regional 
and local measures.
---------------------------------------------------------------------------

    \10\ Revised: Background Information Document, Hypothetical 
Nonattainment Areas for Purposes of Understanding the EPA Proposed 
Rule for Implementing the 8-Hour Ozone National Ambient Air Quality 
Standard in Relation to Re-Opened Comment Period--Illustrative 
Analysis Based on 2000-2002 Data. U.S. Environmental Protection 
Agency, Office of Air and Radiation, Office of Air Quality Planning 
and Standards. Draft. October 2003. Available at: http://www.epa.gov/ttn/naaqs/ozone,o3imp8hr/.
    \11\ Qualitative Assessment of Alternative Coverage and 
Classification Options. First Addendum to ``Cost, Emission 
Reduction, Energy, and Economic Impact Assessment of the Proposed 
Rule Establishing the Implementation Framework for the 8-hour, 
0.08ppm Ozone National Ambient Air Quality Standard.'' Prepared by 
Innovative Strategies and Economics Group, Air Quality Strategies 
and Standards Division, Office of Air Quality Planning and 
Standards, Office of Air and Radiation, U.S. Environmental 
Protection Agency, Research Triangle Park, North Carolina. April 8, 
2004.
---------------------------------------------------------------------------

    EPA notes that there are uncertainties at this time about the time 
periods needed for attainment, especially for the limited number of 
areas needing substantial emissions reductions to attain. For example, 
it is difficult to determine in advance of State development of 
attainment plans when such an area will be able to attain the NAAQS. 
These plans are based on high-resolution local air quality modeling, 
refined emissions inventories and detailed analyses of the impacts and 
costs of potential local control measures.
    Another factor is that new methods of achieving cost effective 
emissions reductions are continuing to be developed. Our repeated 
experience over the past three decades is that market forces stimulated 
by the CAA have repeatedly led to technological advances and learning 
through experience, making it possible over time to achieve greater 
emissions reductions at lower costs than originally anticipated.\12\
---------------------------------------------------------------------------

    \12\ For instance, the cost of selective catalytic reduction 
(SCR) catalyst (for control of NOX) has gone from 
$11,000--$14,000/cubic meter in 1998 to $3,500--$5,500/cubic meter 
currently. Advancements in low NOX burner (LNB) 
technology and staged combustion have resulted in sharp 
NOX reductions at much lower costs. New burner 
technologies have lowered NOX emissions reductions by as 
much as 50 percent from previous designs. Costs have decreased from 
$25-38/kW in 1993 to about $15/kW in 2003. Memorandum of October 10, 
2003 from Jim Staudt, Andover Technology Partners, Re: Prime 
Contract 68-W-03-028; Subcontract Agreement 23BL00114; ATP Contract 
:C-03-007.
---------------------------------------------------------------------------

    Other uncertainties reflect use of the most recent three years of 
air quality data for the actual designations and classifications, and 
use of more refined and area-specific modeling methodologies for 
projecting future ozone concentrations.
    Regarding the use of later air quality data, we have interpreted 
the CAA's requirements under section 181 such that we must classify 
nonattainment areas that are covered under subpart 2 based on the most 
recent ozone design values, which are based on three years of data. 
Because of year-to-year variations in meteorology, this ``snapshot in 
time'' may not be representative of the normal magnitude of problems 
that a number of areas face.
    Regarding modeling methodologies, national/regional modeling may 
indicate that a number of moderate areas may face difficulty attaining 
the standard by the maximum attainment date required for an area's 
classification. However, when a State using photochemical grid modeling 
predicts concentrations that are above the NAAQS after application of 
SIP controls, an optional weight of evidence determination which 
incorporates, but is not limited to, other analyses, such as air 
quality and emissions trends, may be used to address uncertainty 
inherent in the application of photochemical grid models. (Issues 
related to implementation of the standard--including issues on the 
attainment demonstration and modeling--will be addressed in the second 
phase of rulemaking.)
    We are aware that some 8-hour nonattainment areas in the Eastern 
U.S. that are classified moderate using 2001-2003 air quality data will 
have difficulty attaining the NAAQS by the attainment date of 2010 (6 
years after designation). We encourage States to request 
reclassification upward where the State finds that an area may need 
more time to attain than their classification would permit. In 
addition, EPA will consider bumping up areas subject to the five 
percent provision of section 181(a)(4) of the CAA on our own initiative 
where there is evidence that an area is unlikely to attain within the 
period allowed by their classification. The rulemaking that sets forth 
designations and classifications for the 8-hour standard discusses 
criteria we would use if we take this action.
    If a State finds during the attainment planning process that 
feasible controls are not available and an area may need more time to 
attain the 8-hour NAAQS than their classification would permit, the 
statute provides a remedy. A State can receive more time to attain by 
voluntarily submitting a request to EPA for a higher classification. 
Section 181(b)(3) of the CAA directs EPA to grant a State's request for 
a higher classification and to publish notice of the request and EPA's 
approval. Although the area would have to meet the additional 
requirements for the higher classification, the same would be true if 
the area had been initially classified higher, under a system that 
placed more areas in higher classifications. Voluntary reclassification 
may be an attractive option if the State is unable to develop a plan 
that demonstrates an area will attain within the time period for its 
assigned classification. Some commenters were concerned that it may be 
difficult to develop support for a voluntary reclassification among 
interested parties. However, we believe such dialogue will lead the 
State to undertake a thorough analysis and balancing of how 
expeditiously the area can attain the NAAQS and the cost of the 
measures needed for attainment as these issues will be foremost in the 
stakeholders' minds.
    The EPA prefers Option 2 rather than the alternatives that place 
more areas into higher classifications because in addition to providing 
a longer maximum timeframe in which to attain, the higher 
classifications impose additional statutorily-mandated requirements. 
While the additional requirements might be appropriate for areas that 
truly need the longer period to attain, it is likely that a number of 
areas that do not need a longer period to attain would also be placed 
in a higher classification under these alternatives. For example, 
several areas that would be covered by subpart 1 under Option 2, and 
which EPA projects are likely to attain the 8-hour levels NAAQS within 
3 years based on existing programs, would be classified

[[Page 23960]]

as moderate areas under Alternative B.\13\ In those areas, the 
additional moderate-area control requirements are unlikely to be needed 
for expeditious attainment.
    The EPA believes that under any of the classification approaches 
that were considered there will be areas that are ``misclassified''--
i.e., the classification will not reflect the time the area needs to 
attain and the level of controls needed. The statute does not allow EPA 
to reclassify an area to a lower classification, except as provided in 
section 181(a)(4) regarding an initial 5 percent adjustment. It does, 
however, as described above, provide continuing authority for areas to 
be reclassified to a higher classification. For that reason, EPA 
believes the better approach is to use a scheme that may classify areas 
too low and areas that need more time to attain can use the voluntary 
reclassification provision of the CAA to obtain the appropriate 
classification.
---------------------------------------------------------------------------

    \13\ Revised: Background Information Document, Hypothetical 
Nonattainment Areas for Purposes of Understanding the EPA Proposed 
Rule for Implementing the 8-hour Ozone National Ambient Air Quality 
Standard in Relation to Re-Opened Comment Period--Illustrative 
Analysis Based on 2000-2002 Data. U.S. Environmental Protection 
Agency, Office of Air and Radiation, Office of Air Quality Planning 
and Standards. Draft. October 2003. Available at: http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.
---------------------------------------------------------------------------

    (ii) How is Option 2 consistent with the CAA as Interpreted by the 
Supreme Court? The legal framework for Option 2 is described in detail 
in the June 2, 2003 proposed rule (68 FR 32813). In short, EPA relies 
on the Supreme Court's recognition that there is a gap in the statute 
with respect to areas ``whose ozone levels are greater than the new 
standard (and thus not attaining) but less than the approximation of 
the old standard codified by Table 1.'' Thus, for areas with a 1-hour 
design value above the level codified in Table 1, EPA interprets the 
Supreme Court as determining that the CAA mandates that they be 
classified under subpart 2. For all other areas, the Court indicates 
there is a gap and EPA must determine a reasonable approach for 
classifying these areas. Option 2 is consistent with the CAA as 
interpreted by the Supreme Court because it places all areas with a 1-
hour design value of 0.121 ppm or greater in subpart 2 and, for the 
reasons provided below, EPA's decision to classify all ``gap'' areas 
under subpart 1 is reasonable.
    As we noted in the June 2, 2003 proposal (68 FR 32814), when faced 
with a similar issue following enactment of the CAA Amendments of 1990, 
we determined that areas that Congress did not mandate fall into the 
classification scheme of subpart 2 should be subject to only the 
planning obligations of subpart 1.\14\ We believe it is appropriate to 
continue that interpretation of the CAA for 8-hour ozone areas--despite 
the fact that a significant number of areas designated nonattainment 
for the 8-hour NAAQS will fall into this group. This decision is 
reasonable because subpart 2 was developed by Congress 13 years ago and 
our scientific understanding of the causes of ozone pollution and the 
transport of ozone and its precursors has significantly advanced. In 
addition, subpart 1 was developed at the time that the 1-hour NAAQS was 
the NAAQS of concern. At that time, many areas had a long-term ozone 
problem that they had been unable to solve under the more flexible pre-
1990 provisions of the CAA. The 8-hour NAAQS is different in many ways 
from the 1-hour NAAQS. Moreover, the areas that will be subject to 
subpart 1 are primarily areas that have not had the long-term pollution 
problem that Congress was concerned about when it created subpart 2.
---------------------------------------------------------------------------

    \14\ These areas included: (a) The transitional areas under 
section 185A (areas that were designated as an ozone nonattainment 
area as of the date of enactment of the CAA Amendments of 1990 but 
that did not violate the 1-hour ozone NAAQS between January 1, 1987, 
and December 31, 1989); (b) nonattainment areas that had incomplete 
(or no) recent attaining data and therefore could not be designated 
attainment; and (c) areas that were violating the 1-hour ozone NAAQS 
by virtue of their expected number of exceedances, but whose design 
values were lower than the threshold for which an area can be 
classified under Table 1 of subpart 2 (submarginal areas). See 57 FR 
13498 at 13524 col. 3 et seq. (April 16, 1992).
---------------------------------------------------------------------------

    Congress enacted subpart 2 with the understanding that all areas 
(except marginal areas, for which few, if any, controls for existing 
sources were required) would have to employ additional local controls 
to meet the 1-hour ozone NAAQS in a timely fashion. Since then, many 
local, regional and national control measures have been implemented, 
our understanding of the importance of interstate pollution transport 
has improved, and we have promulgated interstate NOX 
transport rules to address transported pollution (the NOX 
SIP call, October 27, 1998, 63 FR 53756). Today, regional modeling by 
EPA indicates that the majority of potential 8-hour nonattainment areas 
that fall into the gap will attain the 8-hour NAAQS by 2007 based on 
reductions from the NOX SIP Call, the Federal Motor Vehicle 
Emissions Control Program, and other existing Federal and State control 
measures, without further local controls.
    Some gap areas would be classified as moderate areas if placed 
under subpart 2. The EPA regional modeling shows that many of these are 
projected to attain by 2007 through existing regional or national 
measures. (The proposal provides estimates of the numbers of areas, see 
68 FR 32814, col. 3).\15\ If these areas were to be classified as 
moderate, they would be required to implement statutorily specified 
controls for moderate areas. We believe it is reasonable to adopt an 
approach that would not mandate new local controls in areas projected 
to meet the NAAQS within 3 years through emissions reductions required 
by existing programs.
---------------------------------------------------------------------------

    \15\ See also: Background Information Document, Hypothetical 
Nonattainment Areas for Purposes of Understanding the EPA Proposed 
Rule for Implementing the 8-hour Ozone National Ambient Air Quality 
Standard. Illustrative Analysis Based on 1998-2000 Data. U.S. 
Environmental Protection Agency, Office of Air and Radiation, Office 
of Air Quality Planning and Standards, Draft, April 2003. Available 
at: http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.
---------------------------------------------------------------------------

    Some commenters contended that placing these areas in subpart 1 
created an ``equity'' problem because other areas with a similar 8-hour 
ozone design value would be placed under subpart 2. The EPA considered 
this issue when it reopened the comment period and set forth 
alternatives that would have placed areas with similar 8-hour design 
values in the same classification. While in one light such a situation 
may be perceived as inequitable, EPA believes that this is generally 
not the case. As an initial matter, EPA notes that the areas that fall 
under subpart 2 are areas with higher ozone 1-hour peak 
concentrations--i.e., areas with levels above the 1-hour NAAQS.\16\ 
Thus, the areas classified under subpart 1 do not have the same type of 
ozone problem as those classified under subpart 2 and the same control 
programs may not be needed for both types of areas. We note that the 
areas that will be classified under subpart 2 are the type of area that 
Congress considered at the time that it developed subpart 2 and it is 
more likely that subpart 2 will provide benefits for these areas. We 
also note that in the proposed rule, we proposed several ways to make 
the obligations under subpart 1 similar to those under subpart 2 for 
areas with a similar ozone problem. Thus, there are other means to 
address any inequities; EPA will

[[Page 23961]]

consider equity and other factors in deciding control requirements for 
subpart 1 areas in Phase 2.
---------------------------------------------------------------------------

    \16\ For instance, the range of 1-hour ozone design values of 
the hypothetical subpart 1 areas is from 0.101 ppm to 0.120 ppm, 
with an average of 0.111 ppm. The range of 1-hour design values of 
subpart 2 areas is from 0.122 ppm to 0.175 ppm with an average of 
0.133 ppm. See docket document OAR-2003-0079-0573 (REVISED: 
Background Information Document, Hypothetical Nonattainment Areas 
for Purposes of Understanding the EPA Proposed Rule for Implementing 
the 8-hour Ozone NAAQS in Relation to Re-Opened Comment Period) for 
the data used for these statistics.
---------------------------------------------------------------------------

    Most of the gap areas would be classified as marginal if classified 
under subpart 2 by 8-hour design value.\17\ Because control 
requirements for marginal areas are similar to those for subpart 1 
areas, and because most of these areas are projected to attain within 3 
years, the distinction in regulatory category may make no practical 
difference for many of these areas. However, placing these areas under 
subpart 1 provides States and EPA with greater discretion to handle 
implementation difficulties that might arise in some of these areas. 
For example, a gap area might be unable to attain within the maximum 
attainment date for marginal areas (3 years after designation) because 
of pollution transport from an upwind nonattainment area with a later 
attainment deadline. In that event, subpart 2 would call for the area 
to be reclassified as moderate and for the area to implement additional 
local controls specified for moderate areas. For areas under subpart 1, 
however, we could provide additional time for the area to attain while 
the upwind sources implemented required controls if this were 
determined to be a more effective or more appropriate solution. 
Although regional modeling projections indicate that the NOX 
SIP Call will bring most gap areas into attainment by 2007, some States 
have voiced concern that interstate or intrastate pollution transport 
may make timely attainment difficult for some 8-hour areas with near-
term attainment deadlines (e.g., 2007). Subpart 1 would provide States 
and EPA with more flexibility on the remedy in any such cases, while 
still requiring that subpart 1 areas adopt all reasonably available 
control measures to attain as expeditiously as practicable.\18\ Some 
may perceive the placement of gap areas in subpart 1 (based on their 1-
hour design values) as inequitable compared to placing other areas that 
have similar 8-hour design values in subpart 2 (based on their 1-hour 
design values). We do not believe, however, that it makes sense to 
limit our authority by placing gap areas in subpart 2 even though they 
may have 8-hour design values similar to areas that will be classified 
under subpart 2.
---------------------------------------------------------------------------

    \17\ Background Information Document, Hypothetical Nonattainment 
Areas for Purposes of Understanding the EPA Proposed Rule for 
Implementing the 8-hour Ozone National Ambient Air Quality Standard. 
Illustrative Analysis Based on 1998-2000 Data. U.S. Environmental 
Protection Agency, Office of Air and Radiation, Office of Air 
Quality Planning and Standards, Draft, April 2003. Available at: 
http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.
    \18\ Concern about transport is supported by EPA's modeling for 
the Interstate Air Quality Rule (69 FR 4566, January 30, 2004); EPA 
has proposed to find that in the absence of further controls, 25 
States would significantly contribute to downwind nonattainment in 
other States in 2010, even after the NOX SIP Call has 
been in full effect. As a result, EPA has proposed to require the 25 
States to reduce their emissions of NOX to reduce 
interstate transport, with the reductions to be achieved by 2010 and 
2015.
---------------------------------------------------------------------------

    An advantage of Alternatives A and B was that they avoided or 
reduced equity concerns raised by some commenters with Option 2. 
Regardless, we believe that equity considerations should not override 
other considerations in determining how to best help areas attain the 
8-hour NAAQS. Congress mandated that areas with 1-hour ozone levels 
above the level 0.121 ppm be classified under subpart 2. However, 
Congress did not specifically address the areas that fall into the 
``gap.'' Where Congress has left to EPA's discretion how to classify 
areas, we believe that factors we have considered above \19\ outweigh 
any desire for ``equity.''
---------------------------------------------------------------------------

    \19\ These include trying to meet the following objectives as 
discussed above: (a) Providing flexibility in determining the most 
effective control; (b) achieving attainment at costs lower than 
those for strategies with prescribed measures; (c) providing 
flexibility in addressing nonattainment areas that are have 
difficulty attaining due to transport; and (d) ensuring expeditious 
but reasonable attainment dates.
---------------------------------------------------------------------------

    Additionally, we note that since 1990 we have learned that 
NOX control is more important for many areas than was 
recognized at the time of the 1990 CAA Amendments. Some mandatory 
measures in subpart 2, such as the 15 percent VOC reduction required 
for certain areas, focus on VOC reductions. In some areas it will be 
more effective and less costly to reduce ozone through a strategy that 
places more emphasis on NOX than VOC, and a 15 percent VOC 
reduction may not be part of an optimal strategy. Subpart 1 would allow 
such areas greater flexibility on choice of controls.
    In summary, Option 2 meets the policy goals EPA specified in the 
proposal--most importantly, providing flexibility, and encouraging 
expeditious attainment of the NAAQS--and is consistent with the Supreme 
Court's ruling. Commenters were divided on the merits of different 
classification approaches and no single option appealed to a large 
majority of stakeholders. On balance, EPA determined that Option 2 was 
preferable to the other options identified. Thus, EPA is adopting 
Option 2.
3. Comments and Responses
    This preamble briefly summarizes major comments on each portion of 
the Phase 1 rule and generally provides a brief response to those 
comments. The response to comment (RTC) document presents a more 
complete description of comments received and a more complete response 
to those comments.
    Comment: The commenters were split on whether they preferred Option 
1, under which all areas are classified under subpart 2 of the CAA, or 
Option 2, under which 8-hour nonattainment areas with 1-hour ozone 
design values of 0.121 ppm or greater at the time of designation are 
classified under subpart 2 and all other 8-hour nonattainment areas are 
classified under subpart 1. Those who supported Option 2, indicated it 
made better policy sense, was more flexible and more appropriate than 
Option 1, cost less, was better integrated with other regulations, 
provided more reasonable attainment dates, and was more consistent with 
the Supreme Court decision. A number of commenters supported Option 2, 
but recommended variations of that approach. These commenters raised 
one (or both) of two concerns with the approach recommended by EPA: (1) 
Since most of the areas fall into the lower classifications with short-
term attainment dates, it does not provide sufficient time for many 
areas to attain; and (2) since some areas classified under subpart 1 
will have a more severe 8-hour ozone problem than some areas classified 
under subpart 2, Option 2 is or may be perceived as inequitable. In 
addition, several commenters recommended options different than either 
of the options proposed by EPA.
    Those who favored Option 1 argued that it was more consistent with 
the Supreme Court's decision and the CAA, that Subpart 2 was more 
likely to produce progress and faster attainment, was more consistent 
with Subpart 2 of the CAA, was more equitable and fair, and that 
Subpart 1 had other problems that made it less desirable.
    Some commenters claimed both Options 1 and 2 were flawed, based on 
concerns about transport and concerns related to the Supreme Court 
decision. We received comments on the translation of Section 181's 
Table 1. These comments addressed the concerns such as: the proposed 
translation could result in attainment deadlines which are unrealistic 
and unachievable; it would be more logical and more consistent with the 
nature of the standard being implemented--the 8-hour standard--for EPA 
to translate the Table 1 thresholds into approximate 8-hour 
equivalents; and the starting threshold should be different from what 
EPA proposed. Some commenters

[[Page 23962]]

offered other alternatives for the translation and/or the starting 
threshold.
    There were several specific comments related to the draft 
regulatory text.
    Our rationale for adopting Option 2 as the final classification 
approach is presented above. Below is a brief synopsis of the response 
to major comments.
    Response to Comments Supporting Option 2: We generally agree with 
these comments and the final rule incorporates Option 2.
    Response to Comments that Supported Option 2, But Recommending 
Variations That Would Provide More Time for Attainment: Based on our 
projections of future air quality based on regional modeling and 
experience with ozone control in the past, we believe that States may 
find during the attainment planning process that a limited number of 
areas may need more time to attain the 8-hour NAAQS than their 
classification would permit. However, the statute provides a remedy for 
this situation. A State can receive more time to attain by voluntarily 
submitting a request to EPA for a higher classification--including the 
classification they had under the 1-hour NAAQS. The CAA (Section 
181(b)(3)) directs EPA to grant a State's request, and to publish 
notice of the request and EPA's approval. Although the area would have 
to meet the additional requirements for the higher classification, the 
same would be true if the area had been initially classified higher, 
under a classification system that placed more areas in higher 
classifications. The EPA recognizes that voluntary reclassification is 
a legitimate option under the CAA, and may be an attractive option if 
the State is unable to develop a plan that demonstrates an area will 
attain within the time period for its assigned classification. As noted 
in the October 21, 2003 notice reopening the comment period, we 
considered other classification approaches, including those suggested 
by commenters and EPA's Alternatives A and B, which would provide more 
areas with later attainment dates by placing more areas in higher 
classifications. However, EPA found that alternatives that provided 
more time to the areas with the worst ozone problems also provided 
higher classifications, accompanied by additional statutorily-mandated 
requirements, for areas that EPA believes may attain by the 2007 ozone 
season based on projected emissions reductions from existing programs. 
Under these approaches, these areas would be subject to controls that 
may not be necessary for attainment. The EPA believes it is more 
appropriate to use the statutory mechanism for a voluntary bump up for 
areas classified ``too low'' than to mandate controls for areas based 
on a classification that is ``too high.''
    Response to Comments that Noted that Option 2 May Be Perceived as 
Inequitable: A number of other commenters dismissed the 
characterization of Option 2 as being inequitable. The EPA's response 
to the equity issue is discussed above.
    Response to Comments that Recommended Options Different than the 
Options Proposed by EPA: Certain commenters suggested that areas still 
not meeting the 1-hour NAAQS should continue to implement the 1-hour 
NAAQS under subpart 2, but once the NAAQS is attained (or all mandated 
controls were implemented) the area would implement the 8-hour NAAQS 
under subpart 1. All areas attaining the 1-hour NAAQS would begin 
implementing the 8-hour NAAQS under subpart 1.
    As explained more fully in the response to comments (RTC) document, 
EPA does not believe this approach is consistent with the CAA or the 
Supreme Court's decision on implementation of a revised ozone NAAQS. 
The issue before the Court was whether the classification provisions of 
subpart 2 apply for purposes of implementing the revised 8-hour ozone 
NAAQS. The Court unequivocally stated that those provisions do apply 
for purposes of implementing the 8-hour ozone NAAQS. 531 U.S. 482-84. 
We believe that any option that does not provide a role for the subpart 
2 classification structure in implementing the 8-hour NAAQS is not 
consistent with the Court's interpretation of the CAA.
    Commenters suggested several other options, some of which were 
described in our notice reopening the public comment period. Under one 
of these options, we would reduce the range for the subpart 2 
classifications, which would have classified more subpart 2 areas in 
higher classifications, thereby extending the maximum period for 
attainment. We have addressed the problems associated with that kind of 
classification structure above. Under another of these options, the 
classification structure would have relied solely on 8-hour ozone 
design values. This approach was a variant of Option 2 in which all 
areas with 8-hour design value of less than a value that is equivalent 
to the 1-hour value of 0.121 ppm would be covered by subpart 1. This 
variant of Option 2 has the effect of moving source areas from Subpart 
1 to Subpart 2 and at the same time placing more Subpart 2 areas in 
lower classification categories. The Subpart 2 areas placed in these 
lower classification categories would be subject to fewer mandatory 
requirements. However, EPA believes that this approach would increase 
the number of areas for which the initial classification would not 
provide sufficient time to attain.
    The EPA's assessment of these and other options is included in the 
RTC document.
    Response to Comments that Favored Option 1 and Argued that it was 
More Consistent with the Court Decision and the CAA: We believe Option 
2 is a reasonable method for addressing the gaps that the Supreme Court 
recognized in the CAA. Option 2 provides more flexibility than Option 1 
to States and Tribes to design strategies to meet the 8-hour ozone 
NAAQS in the most effective and least costly way considering local 
circumstances, while requiring and providing incentives for expeditious 
attainment of the health-based NAAQS. Since Option 1 would require all 
8-hour nonattainment areas to be covered under subpart 2 with its set 
of prescriptive control measures, it would generally cost more but 
would not require attainment any more expeditiously than Option 2. Both 
subpart 1 and 2 require attainment dates ``as expeditious as 
practicable'' regardless of the maximum attainment dates specified in 
the CAA.
    We believe that Option 2 is consistent both with the CAA and the 
Supreme Court's decision in Whitman as described above and in the June 
2, 2003 proposed rule (68 FR 32813). In short, EPA relies on the 
Supreme Court's recognition that there is a gap in the statute with 
respect to areas ``whose ozone levels are greater than the new standard 
(and thus not attaining) but less than the approximation of the old 
standard codified by Table 1.'' Thus, for areas with a 1-hour design 
value above the level codified in Table 1, EPA interprets the Supreme 
Court as determining that the CAA mandates that they be classified 
under subpart 2. For all other areas, the Court indicates there is a 
gap and EPA must determine a reasonable approach. For the policy 
reasons specified above, in the RTC and in the preamble to the proposed 
rule (68 FR 32814-15), EPA believes it is reasonable to address these 
``gap'' areas under subpart 1.
    Response to Comments Asserting that EPA does not have Authority to 
Modify Table 1 to Reflect 8-Hour Ozone Values: We disagree with those 
commenters who claim EPA does not have authority to modify Table 1 in 
section 181(a) to

[[Page 23963]]

reflect 8-hour design values. We acknowledge that EPA is applying the 
statute other than in the way it is written. We believe we have 
authority to do so because to apply it as written would produce absurd 
results. In enacting the classification structure in subpart 2, 
Congress linked the severity of an area's air quality problem with the 
time needed to attain and the stringency of the controls that an area 
would be required to adopt. Thus, areas with a more significant air 
quality problem were granted more time to attain the NAAQS, but were 
also subject to more stringent controls. If we applied Table 1, as 
written, for purposes of the 8-hour NAAQS, the classification scheme 
would not be related to the severity of the area's 8-hour ozone 
problem.
    If 1-hour values were used to classify 8-hour nonattainment areas 
based solely on Table 1 as presented in section 181 of the CAA, there 
would be 2 serious areas, 9 moderate areas, and 26 marginal areas.\20\ 
Unlike other areas, marginal areas (as explained elsewhere) are not 
subject to the requirement for attainment plans to ensure that they 
identify and adopt the controls necessary for attainment by their 
attainment date. Based on EPA's modeling projections of future ozone 
levels and past experience working with states on ozone SIPs, EPA 
believes it is clear that most of the areas that would be marginal if 
classified by 1-hour design value would fail to attain the 8-hour 
standard without additional local controls by the spring 2007 
attainment date for marginal areas. These include major cities with 
elevated 8-hour ozone levels such as Chicago and Dallas-Fort Worth. In 
fact, over a quarter of these areas that would be marginal if 
classified by 1-hour design values were not projected to attain the 8-
hour NAAQS without additional local controls even by 2010. The 
projection that many of these areas would not attain by 2010 without 
additional controls is further evidence they would not attain in 2007 
without further controls. Thus, for many areas, classifying by 1-hour 
design value would not reflect the severity of their 8-hour ozone 
problem or the time needed to attain.
---------------------------------------------------------------------------

    \20\ Based on data from: Revised: Background Information 
Document, Hypothetical Nonattainment Areas for Purposes of 
Understanding the EPA Proposed Rule for Implementing the 8-hour 
Ozone National Ambient Air Quality Standard in Relation to Re-Opened 
Comment Period--Illustrative Analysis Based on 2000-2002 Data. U.S. 
Environmental Protection Agency, Office of Air and Radiation, Office 
of Air Quality Planning and Standards. Draft. October 2003. 
Available at: http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.
---------------------------------------------------------------------------

    An additional problem is that the practical effect of placing many 
areas that cannot attain by 2007 into the marginal classification would 
be to delay development of plans for improving air quality to meet the 
8-hour standard. This would be inconsistent with Congress's intent, 
reflected in the requirements of the Act, that areas attain air quality 
standards as expeditiously as practicable. Rather, Congress intended 
classifications to approximate the attainment needs of areas. In this 
circumstance, it is appropriate for EPA to make, by way of regulation, 
a limited modification to Table 1 to reflect Congressional intent.
    We recognize that even under the approach adopted by EPA, some of 
the same anomalies will be created. For example, some areas may need 
more time to attain than provided by the area's initial classification. 
However, these anomalies are more limited because the classifications 
more appropriately recognize an area's 8-hour ozone problem. As noted 
above in our discussion on the basis for selecting Option 2, we believe 
the statutory mechanisms such as voluntary bump ups can address these 
inequities in the limited situations in which they arise. In 
comparison, if 1-hour values were used to classify 8-hour nonattainment 
areas based solely on Table 1 as presented in section 181 of the CAA, 
there would only be 2 serious areas, 9 moderate areas, and 26 marginal 
areas. This is a much different distribution than using Option 2, in 
which there would be more areas in the higher classifications (1 
severe-17, 4 serious, 21 moderate) and far fewer (11) marginal areas. 
And, under the adopted approach, the distribution under subpart 2 is 
based on the area's 8-hour design value not its 1-hour design 
value.\21\
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    \21\ Based on data from: Revised: Background Information 
Document, Hypothetical Nonattainment Areas for Purposes of 
Understanding the EPA Proposed Rule for Implementing the 8-hour 
Ozone National Ambient Air Quality Standard in Relation to Re-Opened 
Comment Period--Illustrative Analysis Based on 2000-2002 Data. U.S. 
Environmental Protection Agency, Office of Air and Radiation, Office 
of Air Quality Planning and Standards. Draft. October 2003. 
Available at: http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.
---------------------------------------------------------------------------

    Response to Comments Favoring Option 1 Arguing that Subpart 2 was 
more Likely to Produce Progress and Faster Attainment: Other commenters 
raised concerns that because subpart 1 is less prescriptive than 
subpart 2 and potentially allows later attainment dates for the less 
polluted areas, areas will not in fact attain the 8-hour NAAQS as 
quickly under subpart 1 as they would be required to do under subpart 
2. As evidence, these commenters point to the past failure of areas to 
attain the ozone NAAQS prior to the enactment of subpart 2 in 1990. We 
disagree.
    Subpart 1 and subpart 2 both require areas to attain the 8-hour 
ozone NAAQS as expeditiously as practicable. Thus, the intention of the 
CAA is that regardless of whether an area is covered under subpart 1 or 
subpart 2, it must achieve clean air on the same schedule-- i.e., as 
expeditiously as practicable. In addition, CAA section 172(c)(1) 
requires that a SIP for a nonattainment area ``* * * shall provide for 
implementation of all reasonably available control measures [``RACM''] 
as expeditiously as practicable * * * and shall provide for attainment 
of the [NAAQS].'' In reviewing SIPs for approvability under subpart 1, 
we will evaluate whether the emission control measures in the SIP and 
the timing of implementation comports with the RACM and attainment 
provisions to ensure all RACM are adopted and implemented as 
expeditiously as practicable and that the attainment date is as 
expeditious as practicable. Subpart 1 sets an initial outside 
attainment date of 5 years following designation for the 8-hour NAAQS.
    Subpart 2 sets the earliest outside attainment date as 3 years 
following designation \22\ for marginal areas. Under subpart 2, 
marginal areas are not required to submit attainment demonstrations 
and, for all practical purposes, are not required to adopt additional 
local controls for existing sources.\23\ Thus, in general, Congress 
anticipated that these areas would come into attainment within 3 years 
without significant additional local controls. We believe that most 
areas covered under subpart 1 with air quality problems similar to 
marginal areas will in fact come into attainment with the 8-hour

[[Page 23964]]

NAAQS on a similar timeframe as areas classified as marginal (i.e., 3 
years following designation).\24\ In fact, we believe the prospects for 
near-term attainment based on existing programs are more favorable now 
than they were in 1990 because national and regional control programs 
already in place will achieve substantial reductions in NOX 
and VOC emissions prior to May 2007. These include the regional 
NOX SIP Call, which mandates interstate transport controls 
for certain States by May 31, 2004 (63 FR 53756, October 27, 1998); 
progressively more stringent emissions standards for new cars and 
light-duty trucks issued since 1990, most recently the Tier 2 motor 
vehicle emission standards, and associated sulfur-in-gasoline 
requirements (65 FR 6698, February 10, 2000); and the heavy duty diesel 
rule (66 FR 5002, January 18, 2001).
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    \22\ As provided below, in the section regarding attainment 
dates for the 8-hour ozone NAAQS, subpart 2 actually specifies that 
the attainment period runs from the date of the 1990 CAA Amendments 
rather than the date of designation. However, as we explain in the 
attainment date section, for purposes of 8-hour NAAQS, we believe 
Congress intended those dates to run from the date of designation.
    \23\ The only control obligations mandated for marginal areas 
are that they fix flaws in their RACT rules and their I/M programs 
that existed at the time of the 1990 CAA Amendments. Areas 
designated nonattainment for the 1-hour NAAQS, which were the areas 
with the pre-90 RACT and I/M obligations, have already made these 
corrections. It is unlikely that any areas designated nonattainment 
for the 8-hour NAAQS will not have already made these corrections if 
they have such programs in place.
    \24\ See 68 FR 32814.
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    For areas covered under subpart 1 with an air quality problem 
similar to subpart 2 moderate areas, the presumptive maximum attainment 
date will be 1 year earlier--i.e., 5 years following designation rather 
than 6 years. To receive a later attainment date, section 172(a)(2)(A) 
requires such areas to demonstrate more time is needed based on the 
severity of nonattainment and the availability and feasibility of 
pollution control measures. As to the first factor--severity of 
nonattainment--EPA believes that it would be difficult to justify 
providing a period longer than 6 years since similar areas classified 
under subpart 2 would not have a longer time to attain. Thus, such an 
area would need to demonstrate that the availability and feasibility of 
control measures (including those mandated under subpart 2) would 
justify an extension longer than 6 years. A similar analysis would 
apply if an area with an even more significant air quality problem were 
covered under subpart 1. For this reason, we do not believe that public 
health concerns support classifying all areas with similar air quality 
under subpart 2.
4. Under the Final Classification Approach, How Will EPA Classify 
Subpart 1 Areas? (Section VI.A.4. of Proposal; 68 FR 32813; Section 
51.904 of Draft and Final Rules)
    a. Background. Section 172(a)(1) provides that EPA has the 
discretion to classify areas subject to subpart 1. We proposed two 
options with respect to classifications for areas subject only to 
subpart 1 (68 FR 32813). First, we proposed to create no 
classifications. Second, we proposed to create one classification--an 
interstate overwhelming transport classification for areas that submit 
a modeled attainment demonstration showing the area's nonattainment 
problem is due to overwhelming transport and that meet the definition 
of a rural transport area under section 182(h) of the CAA. As we noted 
in the June 2, 2003 proposal, the area would receive an attainment date 
that is consistent with section 172(a)(2)(A), but that takes into 
consideration the following:
     The attainment date of upwind nonattainment 
areas that contribute to the downwind area's problem; and
     The implementation schedule for upwind area 
controls, regardless of their geographic scope (e.g., national, 
regional, statewide, local).
    This option would partially address Tribal concerns about 
designations where a Tribal area designated nonattainment does not 
contribute significantly to its own problem. This is one of the key 
issues for the Tribes who seek to have economic growth from new sources 
within their jurisdiction but that have difficulty obtaining emission 
reduction offsets from sources located either inside or outside Tribal 
areas.
    b. Summary of final rule. We are adopting the second option but 
modified as a result of comments. We are creating an overwhelming 
transport classification that will be available to subpart 1 areas that 
demonstrate they are affected by overwhelming transport of ozone and 
its precursors and demonstrate they meet the definition of a rural 
transport area in section 182(h). However, areas would not have to 
demonstrate that transport was due solely to sources from outside the 
State (interstate transport) as was implied by the June 2, 2003 
proposal. All other areas that do not qualify for the overwhelming 
transport classification would not be classified. In addition, an area 
may consider the effects of international transport of ozone and 
precursors in determining if the area is affected by overwhelming 
transport.
    An overwhelming transport classification will accomplish several 
purposes. One purpose is to communicate to the public the need for an 
attainment date to account for the control timetable for upwind areas 
whose emissions are overwhelmingly contributing to the area's 
nonattainment problem. An area will be classified as an ``Overwhelming 
Transport Area'' upon full approval of an attainment demonstration SIP 
that demonstrates, using EPA-approved modeling, that the nonattainment 
problem in the area is due to ``overwhelming transport,'' as set forth 
in guidance. The area must also meet that part of the definition of a 
rural transport area in section 182(h) that requires that an area not 
be in or adjacent to a Consolidated Metropolitan Statistical Area 
(CMSA).
    In approving an attainment date for the area, EPA will consider: 
(1) The attainment date of the upwind nonattainment area or areas that 
contribute to the downwind area's problem; and (2) the implementation 
schedule for upwind area controls, regardless of their geographic scope 
(e.g., national, regional, statewide, local).
    In the June 2003 proposal, we proposed that such areas would be 
subject to requirements similar to those that apply to areas classified 
as marginal under subpart 2. We are considering the comments we 
received on the issue of applicable requirements for these subpart 1 
areas and will address this issue after we issue guidance on assessment 
of overwhelming transport.
    In addition, the proposed rule also indicated that we could 
consider more flexibility for conformity for such areas. In our 
proposed transportation conformity rule published on November 5, 2003 
(68 FR 62690), we did not propose any specific conformity flexibility 
for areas affected by ozone transport. However, many of the proposed 
options, including the types of emissions tests used in conformity, 
would be available to areas affected by transport, as well as other 
types of 8-hour ozone areas. In addition, the existing transportation 
conformity rule already provides flexibility in such things as 
transportation modeling requirements for smaller areas with less severe 
local air quality problems. Also, EPA intends to propose in a few 
months more flexible NSR provisions that would apply in such areas.
    We believe the overwhelming transport classification for areas 
covered under subpart 1 is consistent with the CAA and is reasonable. 
We believe that the classification should be restricted to rural areas 
because these areas will generally not have significant sources of 
emissions to control and therefore are not likely to contribute much to 
their own nonattainment problem. There are exceptions, of course, such 
as rural areas with large sources such as power plants, but such areas 
would also need to meet the other criteria for the classification, such 
as not contributing significantly to nonattainment in other areas.
    In determining an attainment date for areas classified as 
``transport,'' we would apply the criteria in section 172(a)(2)(A). The 
second criterion in section 172(a)(2)(A)--the availability

[[Page 23965]]

and feasibility of control measures--will allow EPA to consider the 
effects of transported pollution in setting an appropriate attainment 
date for these areas of no later than 10 years following designation.
    We recognize that there may be areas affected by transport that 
don't meet the definition of rural transport. However, in determining 
attainment dates for areas under section 172(a)(2)(A), we can consider 
the availability and feasibility of control measures; thus, areas that 
do not meet the definition of a rural transport area should be able to 
adopt an attainment date that reflects the time period for reductions 
in upwind areas that are contributing to nonattainment.
    The EPA decided not to exercise its discretion to create additional 
classifications for subpart 1 areas. We do not believe another 
classification is necessary for expeditious attainment of the 8-hour 
NAAQS for these other subpart 1 areas.
    The final rule (section 51.904(a)) provides for a subpart 1 area to 
be classified as an overwhelming transport area if it meets the 
criteria as specified for rural transport areas under section 182(h) of 
the CAA and overwhelming transport guidance that we will issue in the 
future. Although EPA's June 2, 2003 notice referenced an EPA guidance 
document as the criteria for determining the contribution of sources in 
one or more other areas are an overwhelming cause of an area being 
designated nonattainment, we believe that guidance needs to be updated. 
Thus, we are retracting our previous guidance and will issue revised 
guidance. We plan to address control requirements applicable to these 
areas in Phase 2.
c. Comments and Responses
    Comment: Most of the commenters who commented on classifications 
for subpart 1 areas objected to the requirement that to receive an 
overwhelming transport area classification an area must demonstrate 
that it is a rural transport area. Many of these commenters pointed out 
that there are a number of areas that do not meet that definition and 
that do not generate a significant portion of emissions that contribute 
to the area's nonattainment problem. Some also stated that the CAA does 
not mandate this as a criterion and thus the test was unduly 
restrictive. These commenters asked that the availability of the 
overwhelming transport classification be based only on whether an area 
is a victim of overwhelming transport.
    Response: The CAA does not mandate that an area be considered rural 
in order to receive an overwhelming transport classification under 
subpart 1. However, we believe that areas that are not rural, even if 
they are affected to a significant degree by transport, in general 
contribute at least some degree to their own and likely to other areas' 
nonattainment problems. The final rule, therefore, is as proposed--the 
overwhelming transport classification is only available to areas that 
meet the criteria for rural transport areas under section 182(h) of the 
CAA.
    Comment: One commenter suggested EPA provide increased flexibility 
for areas that would be classified as nonattainment, primarily for 
reasons related to transport. A special category for transport areas, 
should be created for areas that are in attainment of the 1-hour 
standard but, if not for the impact of transport, would not be in 
violation of the new 8-hour standard. The regulatory requirements for 
transport area should be minimal and required compliance dates should 
extend out at least as long as the upwind states.
    Response: We note that 8-hour ozone nonattainment areas covered 
under subpart 1 generally will be close to attaining the 1-hour 
standard. We believe the criteria used to determine overwhelming 
transport will invariably result in a situation where an area subject 
to overwhelming transport would be in attainment of the standard but 
for transport. Subpart 1 provides a maximum of 10 years from the 
effective date of nonattainment designation for attainment. We note, 
however, that if such an area believes that it would need an attainment 
date longer than 10 years, it could request to be reclassified under 
subpart 2 to a classification with a longer attainment date. The area 
would, of course, have to meet the requirements of its subpart 2 
classification (either its requested classification or the rural 
transport classification if it so qualifies).
5. Will EPA Adjust Classifications? (Section VI.A.9. of Proposal; 68 FR 
32816; Section 51.903(b) and (c) of Final Rule)
    a. Background. Under sections 181(a)(4) and 181(b)(3), an ozone 
nonattainment area may be reclassified to the next higher or lower 
classification. Section 181(a)(4) of the CAA states:

    If an area would have been classified in another category if the 
design value in the area were 5 percent greater or 5 percent less 
than the level on which such classification was based, the 
Administrator may, in the Administrator's discretion, within 90 days 
after the initial classification, adjust the classification to place 
the area in such other category. In making such adjustment, the 
Administrator may consider the number of exceedances of the national 
primary ambient air quality standard for ozone in the area, the 
level of pollution transport between the area and other affected 
areas, including both intrastate and interstate transport, and the 
mix of sources and air pollutants in the area.

    Section 181(b)(3) requires the Administrator to grant the request 
of any State to reclassify a nonattainment area in the State to a 
higher classification.
    b. Summary of final rule. We are adopting the approach we included 
in the proposal. For areas subject to subpart 2, section 181(a)(4) of 
the CAA provides that classifications may be adjusted upward or 
downward for an area if the area's design value is within 5 percent of 
another classification. If, for example, an area is subject to a 
subpart 2 classification and there is evidence that the area will not 
benefit significantly from local controls mandated by subpart 2 for the 
area's classification and can attain within the time period specified 
for the next lower classification, the area may obtain some relief 
based on the 5 percent rule in the CAA if applicable. In addition, 
section 181(b)(3) requires the Administrator to grant the request of 
any State to reclassify a nonattainment area in the State to a higher 
classification.
    Section 51.903 was revised from the initial draft regulatory text 
language to add the reclassification provisions in section 181(a)(4) 
and 181(b)(3).
c. Comments and Responses
    Comment: Several commenters supported the use of provisions in 
section 181(a)(4) to allow adjustment of a classification. Comments 
indicated that this approach could result in cost savings in cases 
where the increased controls of the higher classification would not be 
needed for attainment. One commenter noted that the Administrator 
should consider several factors in making the adjustment under section 
181(a)(4), including the number of exceedances of the NAAQS and 
complexity of the problem. The commenter requested that EPA explain how 
the Administrator would make this decision and the process that will be 
used. Another commenter recommended that the actual test of compliance 
with the provisions of section 181(a)(4) should include allowance for 
meteorological fluctuation in order to avoid States having to meet an 
average design value well below the NAAQS before deemed in compliance.
    Response: The EPA's guidance on the 5 percent bump down provision 
in section 181(a)(4) is contained in the November 6, 1991 Federal 
Register (56 FR 56698) which established the initial

[[Page 23966]]

designations and classifications. In a separate Federal Register 
notice, EPA will invite States to submit bump down requests. The EPA 
will describe the criteria (including any changes from the 1991 
criteria) for approval of 5 percent bump downs in that notice and will 
provide at least a 30-day period for States to submit their requests. 
Section 181(a)(4) authorizes the Administrator to adjust a 
classification within 90 days after the initial classification. The EPA 
continues to believe, as provided in the June 2, 2003 proposal, that 
section 181(a)(4) does not provide a basis for an area to move from 
subpart 2 to subpart 1.
6. Proposed Incentive Feature (Section VI.A.6. of Proposal; See 68 FR 
32815; 51.903(b) of Draft Rule)
    a. Background. In the proposed rule (68 FR 32815), we sought 
comment on a classification feature that would allow areas classified 
under subpart 2 to qualify for a lower classification upon a 
demonstration the area would attain the 8-hour NAAQS by the earlier 
attainment date of a lower classification. For example, an area that 
would be classified ``moderate'' based on its 8-hour design value would 
qualify for a ``marginal'' classification by demonstrating it would 
attain the 8-hour NAAQS within 3 years of designation.
    b. Summary of final rule. We are not including the proposed 
incentive feature in the final rule. We received numerous adverse 
comments on the idea, raising both legal and policy issues. Because we 
agree as a policy matter that we should not adopt the incentive 
feature, we do not reach the legal issue of whether the statute grants 
such authority. Our basis for this decision is provided more fully in 
the RTC document, portions of which are excerpted below. In short, we 
believe that only a few areas would have benefitted from this proposal 
considering the flexibility already available under classification 
Option 2, and we believe that the difficulties in developing and 
implementing such an approach outweigh any benefits. In particular, 
commenters on the June 2, 2003 proposal were concerned that we did not 
identify the type of modeling that areas could rely on to take 
advantage of this option. While we had not identified in the June 2, 
2003 proposal the type of modeling that could be used, we had 
referenced our current modeling guidance in the draft regulatory text 
which was published on August 6, 2003. Additionally, we believe it 
would be very difficult for an area to have completed the necessary 
modeling and for us to approve such a SIP submission much in advance of 
the attainment date for a marginal area. Further, if the area did not 
meet that attainment date, it would need to begin the modeling process 
over again almost immediately. We now believe that it makes more sense 
for the area to prepare the modeling required for its higher 
classification and, if the area attains the NAAQS earlier than the 
attainment date for its classification, our Clean Data Policy \25\ will 
provide relief from RFP requirements.
---------------------------------------------------------------------------

    \25\ Memorandum of May 10, 1995, ``RFP, Attainment 
Demonstration, and Related Requirements for Ozone Nonattainment 
Areas Meeting the Ozone National Ambient Air Quality Standard,'' 
from John S. Seitz, Director, Office of Air Quality Planning and 
Standards. Available at: http://www.epa.gov/ttn/oarpg/t1/memoranda/clean15.pdf.
---------------------------------------------------------------------------

c. Comments and Responses
    Comment: About half the commenters that addressed this issue 
opposed the incentive feature. These comments originated mainly from 
environmental organizations and some State and local air pollution 
control agencies and organizations. Many of these commenters questioned 
the legal basis for such a feature and also believed modeling is too 
inaccurate or unreliable to be used for classification purposes. They 
believed that monitoring data should be the sole basis for 
classifications. The other comments received on this issue supported 
the incentive feature. These comments originated mainly from industrial 
representatives and organizations, as well as several State and local 
air agencies and transportation agencies and organizations.
    Response: Our analysis indicates that the incentive feature would 
not have helped very many areas. Of 21 hypothetical nonattainment areas 
classified as moderate (based on 2000-2002 air quality data), our 
modeling projects that only 3 would have qualified without first 
adopting further controls. No serious or higher classified area would 
have qualified without further controls. Very few areas would even 
receive a classification higher than moderate. In addition, even if we 
adopted this approach, we do not believe there would have been enough 
time for areas seeking a marginal classification to submit a plan with 
local controls that demonstrate attainment by a Spring attainment date 
in 2007 and implement the controls by the Spring of 2006. In addition, 
we would have to develop guidance for the demonstration. Furthermore, 
although many commenters supported having the feature, many other 
commenters objected to the feature on a number of grounds. Because of 
the difficulties involved in administering such a program, the 
unfavorable timing, and the anticipated low number of areas that could 
benefit from the feature, we are not incorporating the feature in the 
final rule.
    A number of commenters who opposed the feature contended that the 
approach was not supported by the CAA. Since we are not adopting the 
feature in the final rule on policy grounds, we do not address the 
legal issues here.

B. How Will EPA Treat Attainment Dates for the 8-Hour Ozone NAAQS? 
(Section VI.B. of Proposal; See 68 FR 32816; 51.903 and 51.904 Draft 
and Final Rules)

1. Background
    Under Subpart 2 of the CAA, maximum attainment dates are fixed as a 
function of a nonattainment area's classification under Table 1. The 
CAA provides that an area's attainment date must be ``as expeditious as 
practicable but no later than'' the date provided in Table 1 for that 
area's classification. The statutory dates are specified as a set 
number of years from the date of enactment of the CAA Amendments of 
1990. Since a strict application of Table 1 would produce absurd 
results for most areas (i.e., areas classified as marginal would have a 
November 15, 1993 attainment date, moderate areas would have a November 
15, 1996 attainment date, etc.), we are promulgating a targeted 
revision of Table 1 to reflect attainment dates consistent with 
Congressional intent.
    While the attainment dates in Table 1 are expressly linked to the 
date of enactment of the CAA Amendments of 1990, this is also the date 
on which most areas were designated and classified as a matter of law. 
In addition, as explained in the preamble to the proposed rule (68 FR 
32817), other provisions of the CAA specify that the date for 
attainment shall run from the date of designation and/or classification 
as a matter of law for an area. Consistent with this, we proposed that 
the starting point for the set timeframes for attainment would be the 
date an area is designated and classified for purposes of the 8-hour 
NAAQS.\26\ Thus, for example, an area classified as marginal for the 8-
hour NAAQS would have up

[[Page 23967]]

to 3 years from designation to meet that NAAQS and a moderate area 
would have up to 6 years from designation to attain.
---------------------------------------------------------------------------

    \26\ As explained in our proposed rule, areas will be classified 
as a matter of law at the same time they are designated; thus, we 
simply refer to ``designation'' rather than designation and 
classification.
---------------------------------------------------------------------------

    For areas covered under subpart 1, attainment dates are set under 
section 172(a)(2)(A), which provides that the SIP must demonstrate 
attainment as expeditiously as practicable but no later than 5 years 
after designation, with up to 10 years after designation permitted if 
the severity of the area's air pollution and the availability and 
feasibility of pollution control measures indicate more time is needed. 
In the draft regulatory text, we provided that EPA would establish the 
attainment date for an area at the time we approve the area's 
attainment demonstration.
2. Summary of Final Rule
    We are adopting the time periods for attainment that we proposed 
for areas under both subpart 1 and subpart 2 of the CAA. For areas 
subject to subpart 2 of the CAA, the maximum period for attainment will 
run from the effective date of designations and classifications for the 
8-hour NAAQS and will be the same periods as provided in Table 1 of 
section 181(a):

 Marginal--3 years,
 Moderate--6 years,
 Serious--9 years,
 Severe--15 or 17 years, and
 Extreme--20 years.
    We are adopting this approach because applying the table, as 
written, would produce absurd results. For the reasons above and 
discussed in the preamble to the proposed rule, we believe it is 
consistent with Congressional intent to begin the time periods for 
attainment specified in Table 1 in section 181(a) at the time of 
designation and classification.
    Consistent with section 172(a)(2)(A), for areas subject to subpart 
1 of the CAA, the period for attainment will be no later than 5 years 
after the effective date of the designation. However, EPA may grant an 
area an attainment date no later than 10 years after designation, if 
warranted based on the factors provided in section 172(a)(2)(A). The 
EPA will establish an attainment date for each subpart 1 area at the 
time we approve an attainment demonstration for the area.
3. Comments and Response
    Comment: Several commenters reiterated the CAA's requirement that 
areas attain the NAAQS as ``expeditiously as practicable.'' They felt 
that the attainment deadlines in the proposed rule would impede the 
progress that areas have made and would subject the general public to 
years of unhealthy air quality. One commenter suggested that EPA create 
enforceable short-term compliance dates to assure citizens of downwind 
States that upwind States are meeting their longer-term compliance 
deadlines. Other commenters felt that the attainment dates under both 
subpart 1 and 2 that were proposed did not provide enough time for 
areas to attain for a number of reasons, such as: areas would not be 
able to take credit for emissions reductions from Federal measures, the 
slow turnover of mobile source fleets would not achieve the needed 
mobile source reductions in the timeframes proposed, EPA's Clear Skies 
modeling shows that a number of areas in the mid-Atlantic and northeast 
will not come into attainment before the middle of the next decade, it 
would not be feasible to have stationary and mobile source controls in 
place 3 years before the attainment dates for purposes of monitoring, 
etc. However, a number of commenters agreed with EPA's proposal to 
establish attainment dates that correspond to the timeframes 
established under subpart 2 of the CAA from the date of 8-hour 
nonattainment designations. In addition, one commenter stated that the 
proposal did not clearly address how attainment dates for subpart 1 
areas would be set. Finally, several commenters recommended that EPA 
change the attainment dates to November or December of the attainment 
year rather than in April so areas can use the ozone season air quality 
data from the attainment year to demonstrate attainment.
    Response: As stated in our June 2, 2003 proposal, under subpart 2 
of the CAA, maximum attainment dates are fixed as a function of a 
nonattainment area's classification under Table 1. The CAA provides 
that an area's attainment date must be ``as expeditious as practicable 
but no later than'' the date prescribed in Table 1 for that area's 
classification. The dates were specified as the number of years from 
the date of enactment of the CAA Amendments, which was November 15, 
1990, which was also the date of designation and classification by 
operation of law for most subpart 2 areas. We believe that applying the 
attainment dates as expressly provided under Table 1 would produce 
absurd results, since a strict application of Table 1 would result in 
an attainment date of November 15, 1993 for marginal areas and an 
attainment date of November 15, 1996 for moderate areas. Although we 
believe a strict application of the statute would produce absurd 
results, we do not believe that allows broad authority to re-write the 
statute. Rather, we look to the legislative history and other 
provisions of the CAA to discern Congressional intent. Consequently, 
for the reasons provided above and in the preamble to the proposed 
rule, we have determined that attainment dates will run from the 
effective date of designations and classifications for the 8-hour ozone 
NAAQS. Since we are designating and classifying areas for the 8-hour 
ozone NAAQS with an effective date of June 15, 2004, the corresponding 
attainment periods would run from June 15, 2004.
    We do not believe we have authority to change the attainment dates 
to November or December of the attainment year as several commenters 
requested. We believe that Congress would have intended for areas 
designated nonattainment and classified under subpart 2 for the 8-hour 
NAAQS to have attainment periods consistent with those in Table 1 
(e.g., 3 years for marginal areas, 6 years for moderate areas, etc.) 
This would result in the 8-hour marginal attainment date being 3 years 
from the effective date of designations for the 8-hour NAAQS (i.e., 
June 15, 2007), the moderate attainment being 6 years from the 
effective date of designations for the 8-hour NAAQS (i.e., June 15, 
2010), etc.
    Additionally, EPA does not have the authority to shorten attainment 
dates or lengthen attainment dates to allow areas to take credit for 
emissions reductions from future Federal or regional measures as 
several commenters suggested. The statute provides for all areas to 
attain as expeditiously as practicable. As part of its attainment 
demonstration, a State must demonstrate that there are no reasonably 
available controls that can expedite attainment. Therefore, States must 
address why they cannot attain earlier than the maximum attainment 
date. As to longer attainment dates, States may request a voluntary 
bump up if they believe an area cannot attain by its maximum statutory 
attainment date through the adoption of RACM.
    For areas classified under subpart 1, attainment dates will be set 
under section 172(a)(2)(A), which provides that the SIP must 
demonstrate attainment as expeditiously as practicable but no later 
than 5 years after designation or 10 years after designation if the 
severity of the area's air pollution and the availability and 
feasibility of pollution control measures indicate more time is needed. 
Under subpart 1, we will establish an attainment date for an area at 
the time we approve an attainment demonstration for the area. The State

[[Page 23968]]

must support that the attainment date is expeditiously as practicable 
and must justify any attainment date later than 5 years using the 
factors in section 172(a)(2)(A). The attainment date will be the date 
in the approved SIP. Thus, if an area submits an approvable attainment 
demonstration showing that they can attain the 8-hour NAAQS in, e.g., 4 
years, the area's attainment date will be 4 years from the effective 
date of designations for the 8-hour NAAQS.
4. How Will EPA Address the Provision Regarding 1-Year Extensions? 
(Section VI.B.2 of Proposed Rule; 68 FR 32817; Sections 51.907 of Draft 
and Final Rules)
    a. Background. In limited circumstances, both subpart 1 and subpart 
2 of the CAA provide for two brief attainment date extensions for areas 
that do not attain by their attainment date. Section 172(a)(2)(C) of 
subpart 1 (which applies for all NAAQS) provides for EPA to extend the 
attainment date for an area by 1 year if the State has complied with 
all requirements and commitments pertaining to the area in the 
applicable implementation plan and no more than a minimal number of 
exceedances of the NAAQS has occurred in the area in the attainment 
year. Up to two 1-year extensions may be issued for a single 
nonattainment area.
    Section 181(a)(5) of subpart 2 contains a similar provision for the 
ozone NAAQS, but instead of providing for an extension where there has 
been a ``minimal'' number of exceedances, it allows an extension only 
if there is no more than one exceedance of the NAAQS in the year 
preceding the extension year. The language in section 181(a)(5) 
reflects the form of the 1-hour ozone NAAQS, which is exceedance-based 
and does not reflect the 8-hour ozone NAAQS, which is concentration-
based.\27\ We proposed that since section 181(a)(5) does not reflect 
the form of the 8-hour NAAQS and application would produce an absurd 
result, it was reasonable to interpret this provision in a manner 
consistent with Congressional intent, but reflecting the form of the 8-
hour NAAQS. In addition, we proposed to apply the test in section 
172(a)(2)(C), which applies to areas subject to subpart 1, in the same 
manner as we apply the test under section 181(a)(5) for areas subject 
to subpart 2. Specifically, we proposed that an area would be eligible 
for the first 1-year extension under section 172(a)(2)(C) and under 
181(a)(5) if, for the attainment year, the area's 4th highest daily 8-
hour average is 0.084 ppm or less. The area will be eligible for the 
second extension if the area's 4th highest daily 8-hour value, averaged 
over both the original attainment year and the first extension year, is 
0.084 ppm or less.
---------------------------------------------------------------------------

    \27\ The 1-hour NAAQS, an exceedance-based NAAQS, is basically 
allowed to be exceeded an average of only once a year over a 3-year 
period. (This is a generalization of how attainment is determined; 
the actual method considers other factors such as completeness of 
the data.) See 40 CFR, appendix H. In contrast, the level of the 8-
hour NAAQS (0.08 ppm, 8-hour average) can be ``exceeded'' more than 
once a year on average because the form (concentration-based) of 
that NAAQS is determined by averaging the 4th high reading for each 
year over a 3-year period. Section 50.10(b) provides that the 8-hour 
NAAQS is met at an ambient air quality monitor when the average of 
the annual fourth-highest daily maximum 8-hour average ozone 
concentration is less than or equal to 0.08 ppm. 40 CFR part 50, 
appendix I. Example 1 in appendix I provides an example of an 
ambient monitoring site attaining the 8-hour ozone NAAQS. The 
example shows that over a 3-year period, there were 10 exceedances 
of the level of the 8-hour ozone NAAQS, or an average of 3.33 
exceedances per year.
---------------------------------------------------------------------------

    b. Summary of final rule. We are adopting the interpretation that 
we proposed on June 2, 2003. Under both sections 172(a)(2)(C) and 
181(a)(5), an area will be eligible for the first of the 1-year 
extensions under the 8-hour NAAQS if, for the attainment year, the 
area's 4th highest daily 8-hour average is 0.084 ppm or less. The area 
will be eligible for the second extension if the area's 4th highest 
daily 8-hour value, averaged over both the original attainment year and 
the first extension year, is 0.084 ppm or less.
    We believe that it would be absurd to apply section 181(a)(5) as 
written for purposes of the 8-hour ozone NAAQS. This section was 
written with the form of the 1-hour NAAQS in mind. For purposes of the 
1-hour NAAQS, an area is violating the NAAQS if it has more than three 
exceedances of the NAAQS at a monitor over a 3-year period. Thus, if an 
area is averaging more than one exceedance per year at a monitor, it is 
violating the NAAQS. For the 1-hour NAAQS, it makes sense to consider 
whether there has been more than one exceedance in the attainment year 
for purposes of granting an extension because two or more exceedances 
indicate a significant likelihood the area will not be able to attain 
the NAAQS with a 1-year extension of the attainment date since four 
exceedances over a 3-year period mean the area is violating the NAAQS.
    For the 8-hour NAAQS, violations are determined based on the 
concentration as determined by averaging the 4th highest reading at a 
monitor over a 3-year period. Thus, for each monitor (with complete 
data), the fourth highest readings for each of 3 consecutive years are 
averaged to determine whether an area is violating the NAAQS. If the 
average of those readings is at or above 0.085, then the area is 
violating the 8-hour ozone NAAQS. Unlike the 1-hour NAAQS, an area 
could have several exceedances of the 8-hour NAAQS in the attainment 
year and still be on track to attain the NAAQS the following year since 
attainment is based on an average of the fourth highest reading. For 
this reason, and as we proposed, we believe it makes sense to allow for 
the two 1-year attainment date extensions under section 181(a)(5), 
based on the 4th highest reading at a monitor rather than based on the 
number of exceedances. We are interpreting the phrase ``minimal number 
of exceedances'' in section 172(a)(2)(C) to apply in the same manner.
c. Comments and Response
    Comment: The commenters generally supported EPA's proposed 
interpretation for granting up to two 1-year attainment date 
extensions. One commenter requested clarification that the 4th highest 
daily average 8-hour ozone concentration would be used to grant the 
first extension and the 4th highest daily average 8-hour ozone 
concentration of the attainment year and first extension year would be 
used to determine eligibility for the second 1-year attainment date 
extension. The commenter further expressed support for this approach 
since it is consistent with how EPA determines whether an area is 
violating the 8-hour NAAQS.
    Response: No commenters opposed this aspect of EPA's proposal. 
However, we are re-stating that the 4th highest daily average 8-hour 
ozone concentration would be used to grant the first 1-year extension 
and the 4th highest daily average 8-hour ozone concentration of the 
attainment year and first extension year would be used to determine 
eligibility for the second 1-year attainment date extension.

C. How Will EPA Implement the Transition From the 1-Hour to the 8-Hour 
NAAQS in a Way To Ensure Continued Momentum in States' Efforts Toward 
Cleaner Air? (Section VI.C. of the Proposal; See 68 FR 32818; 51.905 of 
Draft Rule)

    There are two key issues that EPA considered together regarding the 
transition from the 1-hour NAAQS to the 8-hour NAAQS: (1) When will the 
1-hour NAAQS no longer apply (i.e., be ``revoked''); and (2) what 
protections are in place to ensure that, once the 1-hour NAAQS is 
revoked, air quality will not degrade and that progress toward

[[Page 23969]]

attainment will continue as areas transition from implementing the 1-
hour NAAQS to implementing the 8-hour NAAQS. As in the proposed rule, 
the second key issue has three components: (1) What requirements that 
applied based on an area's classification for the 1-hour NAAQS must 
continue to apply to that area; (2) for how long; and (3) in what 
geographic area. Below, we set forth our final transition approach in 
four parts: (1) When will the 1-hour NAAQS no longer apply (i.e., when 
will it be revoked); (2) what 1-hour obligations should continue to 
apply once the 1-hour NAAQS is revoked; (3) how long should those 
requirements continue to apply; and (4) what is the geographic area 
subject to the requirement?
1. When Will EPA Revoke the 1-Hour NAAQS? (Section VI.C.2. of Proposal; 
See 68 FR 32819; Section 50.9.b. of Proposed and Final Rules)
    a. Background. In the proposed rule (68 FR 32819), EPA provided an 
in-depth discussion of the background of the transition rule (40 CFR 
50.9(b)) and policy as established in July 1997 and as subsequently 
revised in response to the ongoing litigation over the 8-hour ozone 
NAAQS and court decisions (68 FR 32818-19). In short, at the time the 
8-hour NAAQS was promulgated in 1997, EPA anticipated that areas would 
implement the 8-hour ozone NAAQS under subpart 1. Areas that were not 
meeting the 1-hour NAAQS were obligated to continue to meet that NAAQS 
and would remain subject to most of the requirements that applied due 
to the area's 1-hour classification, including obligations under 
subpart 2 (62 FR 38873). Although EPA concluded in the NAAQS rulemaking 
that the 1-hour NAAQS was not necessary to protect public health and 
that the 8-hour NAAQS would replace the 1-hour NAAQS (62 FR 38863), we 
determined to delay revocation of the 1-hour NAAQS for areas not yet 
meeting that NAAQS in order to facilitate continued implementation of 
the 1-hour obligations (62 FR 38873). Thus, we promulgated a rule 
providing for the phase-out of the 1-hour ozone NAAQS on an area-by-
area basis based upon a determination by EPA for each area that it had 
met the 1-hour NAAQS (40 CFR 50.9(b), as promulgated at 62 FR 38894) 
(``revocation rule'').
    Subsequently, because the pending litigation over the 8-hour NAAQS 
created uncertainty regarding the 8-hour NAAQS and our implementation 
strategy, we placed two limitations on our authority to apply the 
revocation rule: (1) the 8-hour NAAQS must no longer be subject to 
legal challenge, and (2) it must be fully enforceable.\28\ (65 FR 
45182, July 20, 2000).
---------------------------------------------------------------------------

    \28\ In addition, in June 2003, we stayed our authority to apply 
the revocation rule pending our reconsideration in this rulemaking 
of the basis for revocation. (68 FR 38160, June 26, 2003).
---------------------------------------------------------------------------

    Ultimately, the Supreme Court struck down the implementation 
strategy provided for in the preamble to the final NAAQS rule. Although 
the Court agreed with EPA's conclusion that the statute was ambiguous 
as to how a revised, more stringent ozone NAAQS should be implemented, 
the Court found unreasonable the implementation strategy EPA 
anticipated at the time the 8-hour NAAQS was promulgated. Because EPA 
believes the time at which the 1-hour NAAQS should no longer apply is 
inextricably linked to the overall implementation strategy, EPA 
determined that it should reconsider 40 CFR 50.9(b) in the context of 
this rulemaking. (68 FR 32818-19).
    Consistent with the decision of the Supreme Court, our proposed 
June 2003 implementation rule anticipated that some, if not all, 8-hour 
ozone nonattainment areas would implement that NAAQS under subpart 2 of 
the CAA. There was no longer the clear cut dichotomy that we 
anticipated in 1997--i.e., that 8-hour implementation would occur under 
subpart 1 and 1-hour implementation would continue to occur under 
subpart 2. Thus, the approach from 1997--where we retained the 1-hour 
NAAQS for areas that had not met it in order to make clear that such 
areas retained subpart 2 obligations--merited reconsideration. In 
addition, we indicated that the area-by-area approach to revocation of 
the NAAQS was needlessly burdensome and that it made more sense to 
promulgate one rule establishing the date of revocation of the 1-hour 
NAAQS for all areas.
    With respect to the time at which the 1-hour NAAQS should no longer 
apply to areas, we sought comment on two options. Under Option 1, we 
would revoke the 1-hour NAAQS in full 1 year after the effective date 
of designations for the 8-hour NAAQS. The key consideration for when 
the NAAQS would be revoked was the time at which areas designated 
nonattainment for the 8-hour NAAQS would be subject to conformity 
requirements for the 8-hour ozone NAAQS and our concern that areas not 
be subject to conformity for both the 8-hour and the 1-hour NAAQS at 
the same time. We believed that since our proposed anti-backsliding 
provisions would ensure that progress toward clean air continued and 
would obligate areas to continue to meet the control obligations 
associated with the area's 1-hour classification, there was no need to 
retain the NAAQS and the associated designations and classifications.
    Under Option 2, we proposed to retain the NAAQS itself (and the 
associated designations and classifications) for limited purposes 
(viz., those identified and discussed in section VI.C.3. of the 
proposed rule, which are the same obligations that would continue to 
apply under Option 1). For all remaining purposes, we would revoke the 
1-hour NAAQS and the associated designations and classifications 1 year 
after the effective date of designations for the 8-hour NAAQS. This 
approach would not create a different substantive result than Option 1; 
under both Options, areas would remain subject to the same obligations 
that applied based on their 1-hour classification. Rather, Option 2 was 
based on a somewhat different legal rationale than Option 1.
    b. Summary of final rule. We are adopting Option 1. We will revoke 
the 1-hour NAAQS in full, including the associated designations and 
classifications, 1 year following the effective date of the 
designations for the 8-hour NAAQS. However, we are adopting strong 
anti-backsliding provisions which preserve control obligations mandated 
by subpart 2 for an area's classification for the 1-hour NAAQS. In 
light of the anti-backsliding provisions, the deciding factor 
supporting the schedule for revocation is the conformity obligation for 
areas. We believe it is unnecessary to require areas to meet conformity 
for both the 1-hour and 8-hour NAAQS at the same time; equally 
important, however, is the need to ensure that there is no time when 
conformity stops applying for areas that are subject to it under the 1-
hour NAAQS and designated nonattainment for the 8-hour NAAQS. Thus, we 
are adopting a regulation that provides for revocation of the 1-hour 
NAAQS 1 year following the effective date of the designation of the 
area for the 8-hour NAAQS since that is the time an area designated as 
nonattainment for the 8-hour NAAQS will be subject to conformity 
requirements for the 8-hour NAAQS.
    Our final anti-backsliding provisions will ensure that mandatory 
subpart 2 control measures that applied due to an area's classification 
under the 1-hour NAAQS will continue to apply after the 1-hour NAAQS is 
revoked in full.
    Many commenters believed, and we agree, that Option 1 is a clearer 
approach than Option 2. Since both

[[Page 23970]]

options would lead to the same substantive result, we are adopting the 
clearer approach. Many commenters recommended alternatives other than 
those proposed by EPA. Our basis for rejecting these approaches is 
provided below and in the RTC document.
    c. Comments and responses.
    Comment: Most of the comments we received addressed the issue of 
when we should revoke the 1-hour NAAQS. About half of the commenters 
favored revocation of the 1-hour NAAQS in full 1 year after the 
effective date of the 8-hour designations (proposed Option 1). Only a 
handful of commenters favored partial revocation of the 1-hour NAAQS 
(proposed Option 2). Almost a third of the commenters who addressed 
this issue opposed revocation of the 1-hour NAAQS. Many of the 
commenters in this group insisted that EPA should retain the 1-hour 
NAAQS because it is necessary to protect public health and some noted 
that it may be more protective of public health than the 8-hour NAAQS 
in several areas such as the South Coast and Houston. A number of these 
commenters also suggested that revocation would be contrary to the CAA 
and Congressional intent. Several commenters recommended alternative 
means or timing for the revocation of the 1-hour NAAQS, including a 
recommendation to revoke the 1-hour NAAQS immediately upon designations 
for the 8-hour NAAQS.
    Response to Major Comments: Several commenters opposed revocation 
at all because they believe the 1-hour NAAQS is necessary to protect 
public health. The issue of whether the 1-hour NAAQS is necessary to 
protect public health is a standard-setting issue that was resolved in 
1997. At that time, EPA determined that it was not necessary to retain 
the 1-hour NAAQS as a NAAQS in order to protect public health. In 
setting the 8-hour NAAQS in 1997, we concluded that replacing the 
current 1-hour NAAQS with an 8-hour NAAQS is appropriate to provide 
adequate and more uniform protection of public health from both short-
term (1 to 3 hours) and prolonged (6 to 8 hours) exposures to ozone in 
the ambient air (62 FR 38863). The sole issue here is how and when the 
transition from implementation of the 1-hour NAAQS to implementation of 
the 8-hour NAAQS should occur.
    We believe the strong anti-backsliding provisions in section 51.905 
will ensure that not only will controls already adopted under the 1-
hour NAAQS continue to be implemented until an area attains the 8-hour 
ozone NAAQS, but also that there will be no or minimal delay in 
obtaining additional emissions reductions comparable to those that 
would have been required had the 1-hour NAAQS remained in place. 
Although attainment of the 1-hour NAAQS would no longer be a goal, the 
provisions of section 51.905 would retain the ROP obligations that 
would have been required under the 1-hour NAAQS. Furthermore, the 
provisions of section 51.905 also would retain an area's obligation to 
either expeditiously complete the 1-hour attainment demonstration or 
obtain emissions reductions toward meeting the 8-hour NAAQS that 
substitute for those that would have been required had an area 
completed its attainment demonstration on a schedule more expeditious 
than that required solely for the 8-hour NAAQS. Thus, retaining the 1-
hour NAAQS itself would become largely superfluous from the standpoint 
of obtaining timely emissions reductions.
    We disagree with comments that recommended that EPA revoke the 1-
hour NAAQS immediately upon a nonattainment designation for the 8-hour 
NAAQS. We believe that such timing would create a gap when conformity 
would not apply in the year following designation under the 8-hour 
NAAQS (since conformity does not apply for the 8-hour NAAQS until 1-
year after designation).
    Comment: A major concern raised by commenters was that if the NAAQS 
were revoked, areas would no longer have to meet the SIP budgets 
established for the 1-hour NAAQS for conformity purposes. These 
commenters were concerned that 8-hour ozone nonattainment areas that 
were nonattainment or maintenance for the 1-hour NAAQS would be able to 
determine conformity using another less protective test, such as the 
``build/no-build'' test. One commenter said that if conformity is 
weakened, billions of dollars will be spent on transportation without 
accountability for public health impacts. To avoid these results, 
commenters suggested that conformity requirements for the 1-hour NAAQS 
continue to apply until some other point, such as when budgets for the 
8-hour NAAQS are available, when areas have an approved maintenance 
plan for the 8-hour NAAQS, or the end of areas' 1-hour maintenance 
planning periods (assuming these periods would remain as they are, and 
would not be affected by revocation of the 1-hour NAAQS).
    Response: The EPA proposed conformity regulations for the new 8-
hour ozone NAAQS and new fine particulate matter NAAQS on November 5, 
2003 (68 FR 62690). We proposed that new 8-hour ozone nonattainment 
areas that have 1-hour ozone SIPs would meet one of several tests, and 
the menu of options we offered differed depending on how the 8-hour 
area boundary relates to the 1-hour area boundary. We will consider the 
issues raised by commenters and provide a full response in the context 
of that rulemaking.
    However, at this point EPA can respond to the suggestions to revoke 
the 1-hour NAAQS at a later point such as when 8-hour budgets are 
available, or the end of the 1-hour maintenance planning period. Under 
these scenarios, there would be a period of years where conformity 
would have to be determined for both NAAQS at the same time: a result 
that EPA believes could lead to confusion and additional burden for 
transportation and air quality planners. The EPA believes it is 
sufficient that conformity be determined for one ozone NAAQS at a time. 
Since the 8-hour NAAQS is the health-based standard and it is more 
stringent than the 1-hour NAAQS, we believe conforming to the 8-hour 
NAAQS will be sufficient.
    Comment: One commenter recommended that we provide an option that 
allows States to submit an 8-hour conformity budget early and suspend 
the 1-hour conformity requirements at the time the 8-hour budget is 
determined to be adequate. A second commenter suggested something 
similar, that EPA require States to expedite budgets for the 8-hour 
standard in areas where the 8-hour boundary is larger.
    Response: The EPA did not propose to revoke the 1-hour NAAQS 
earlier than 1 year after designations, in part because we did not 
believe that areas would be able to submit an 8-hour SIP earlier than 
1-year following designation. Furthermore, EPA's proposal was intended 
to align the revocation of the 1-hour NAAQS with the application of 
conformity requirements for the 8-hour NAAQS 1 year after the effective 
date of 8-hour nonattainment designations. The EPA continues to believe 
it is unlikely that areas will have adequate budgets that address the 
8-hour NAAQS before EPA revokes the 1-hour NAAQS. Such budgets cannot 
stand alone but have to be associated with adopted control measures and 
demonstrations of either attainment or RFP, and we believe developing 
these SIPs will take States some time. Once the SIPs are submitted, EPA 
must find them adequate, a process which EPA intends to complete within 
90 days of receiving a SIP. It is unlikely that States will be able to 
complete the work to submit 8-hour ozone SIPs 1 year from the effective 
date of 8-hour ozone area designations, and less likely that States 
will have submitted them

[[Page 23971]]

sufficiently in time for EPA to find them adequate before the 1-hour 
NAAQS is revoked.
    Given these facts and the fact that EPA did not propose an option 
for revoking the standard earlier than 1 year after 8-hour designations 
are effective, EPA does not intend to provide for early revocation of 
the 1-hour NAAQS, nor will EPA require 8-hour areas to expedite 
development of their 8-hour SIP for this purpose. All areas must submit 
SIPs as soon as practicable, and EPA wants States to develop quality 
SIPs to support attainment demonstrations and conformity 
determinations. Prior to the revocation of the 1-hour NAAQS, new 
transportation plan and transportation improvement plan must conform to 
the applicable SIP budgets for the 1-hour NAAQS.
    Comment: Some commenters rebutted EPA's assertion that revoking the 
1-hour NAAQS is necessary so that agencies can focus on planning for 
the 8-hour NAAQS. These commenters stated that neither the revocation 
of the 1-hour NAAQS (or the budgets) is justified on this basis with 
respect to transportation and emissions modeling, because under either 
NAAQS, similar work in establishing base year inventories, and future 
forecasts of travel and emissions must be done. Once the resources are 
in place to make future forecasts, commenters thought that the level of 
effort in both time and money to produce analyses to different regional 
boundaries is relatively small, and ample resources are available to 
pay for the additional analyses needed to determine conformity to both 
NAAQS.
    The EPA also received comments of the opposite opinion. A number of 
commenters supported EPA's proposal that conformity apply for one NAAQS 
at a time. One commenter stated that determining conformity for two 
separate ozone NAAQS would result in undue administrative burden, 
create confusion about requirements in the public process and make 
synchronization of the air quality and transportation planning 
processes more difficult. A couple of commenters argued that having to 
determine conformity for both ozone NAAQS would drain limited resources 
in transportation and environmental agencies. One of these commenters 
contended that demonstrating conformity for two ozone NAAQS could in 
fact delay progress, due to the high administrative burdens.
    Response: While these comments focus solely on the resources 
necessary to determine conformity for both NAAQS, EPA believes a 
discussion of resources should include all aspects of attainment 
planning. Under EPA's proposal, with revocation of the 1-hour NAAQS, 
conformity will no longer apply for that NAAQS as a matter of law. 
Therefore, in order for conformity to apply for both NAAQS as one 
commenter requests, both NAAQS have to be implemented at the same time, 
i.e., the 1-hour NAAQS would have to be implemented in addition to the 
8-hour NAAQS. This would mean continuation of the requirements to 
demonstrate attainment and maintenance of the 1-hour as well as the 8-
hour NAAQS. The EPA believes that it would be a substantial increase in 
burden for States to plan for attainment of both NAAQS, which includes 
conformity but also includes creating inventories for each source 
sector, determining feasible control measures, writing rules to 
implement control measures, permitting stationary sources, establishing 
ROP plans, running iterations of air shed modeling, and demonstrating 
attainment.
    In 1997, EPA determined that the 1-hour NAAQS is not necessary to 
protect public health. Where they are not required by anti-backsliding 
provisions, EPA does not believe that the additional burden States 
would undertake in planning to achieve both the 1-hour and the 8-hour 
NAAQS is necessary to protect public health.
2. What Requirements That Applied in an Area for the 1-Hour NAAQS 
Continue To Apply After Revocation of the 1-Hour NAAQS for That Area? 
(Section VI.C.3. of Proposal; 68 FR 32820; Section 51.905(a) of the 
Draft and Final Rules)
    a. Background. In this section of the June 2, 2003 proposed rule 
(68 FR 32820), we considered what obligations from subpart 2 that 
applied to an area based on its classification for the 1-hour ozone 
NAAQS should continue to apply to such area after it has been 
designated for the 8-hour NAAQS and the 1-hour NAAQS has been revoked. 
We proposed that the continuity of particular obligations may vary 
depending on the attainment status of an area for the 8-hour NAAQS. The 
proposed rule addressed two categories of areas: (1) areas that are 
designated nonattainment for the 8-hour NAAQS and that were designated 
nonattainment for the 1-hour NAAQS on or after November 15, 1990; and 
(2) areas that are designated attainment for the 8-hour NAAQS and that 
were designated nonattainment for the 1-hour NAAQS on or after November 
15, 1990. Furthermore, we divided the types of obligations into four 
categories for purpose of our analysis: (1) Mandatory control measures 
(e.g., NOX RACT, I/M, and fuel programs); (2) discretionary 
control measures (e.g., control measures or other obligations the State 
selected and adopted into the SIP for purposes of attainment, ROP or 
any other goal to benefit air quality, but which are not specifically 
mandated by subpart 2); (3) growth management (NSR); and (4) planning 
activities (attainment and maintenance demonstrations and RFP plans). 
We addressed conformity separately because it is a subpart 1 
requirement. In addition, we addressed the NOX SIP Call 
separately since this obligation applies statewide and without respect 
to the designation status of areas within the State.
    In the draft regulatory text released in August 2003, for areas 
designated nonattainment for the 8-hour NAAQS, we broke into two groups 
the areas designated nonattainment for the 1-hour NAAQS on or after 
November 15, 1990: (1) Areas that remain designated nonattainment for 
the 1-hour NAAQS at the time of revocation of the 1-hour NAAQS; and (2) 
areas that were designated nonattainment for the 1-hour NAAQS but that 
have been redesignated to attainment for the 1-hour NAAQS (i.e., 
``maintenance areas'') at the time of revocation of the 1-hour 
NAAQS.\29\ In response to comments on the proposed rule and draft 
regulatory text, the final regulation creates the same sub-
categorization for areas designated attainment for the 8-hour NAAQS. In 
the final rule and in the preamble discussion below, we also break into 
the same two groups the areas designated attainment for the 8-hour 
NAAQS. Thus, in the preamble and rule we consider the obligations that 
continue to apply for four categories of areas: (1) Areas that remain 
designated nonattainment for the 1-hour NAAQS at the time of 
designation as nonattainment for the 8-hour NAAQS; (2) areas that are 
maintenance areas for the 1-hour NAAQS at the time of designation as 
nonattainment for the 8-hour NAAQS; (3) areas that remain designated 
nonattainment for the 1-hour NAAQS at the time of designation as 
attainment for the 8-hour NAAQS; and (4) areas that are maintenance 
areas for the 1-hour NAAQS at the time of designation as attainment for 
the 8-hour NAAQS. Both the preamble and the rule may use the following 
terms to discuss

[[Page 23972]]

these four categories: (1) 8-hour NAAQS nonattainment/1-hour NAAQS 
nonattainment (2) 8-hour NAAQS nonattainment/1-hour NAAQS maintenance; 
(3) 8-hour NAAQS attainment/1-hour NAAQS nonattainment (4) 8-hour NAAQS 
attainment/1-hour NAAQS maintenance. Under each of these sections in 
the preamble, we address how the final rule treats the four types of 
obligations identified in the proposed rule: (1) Mandatory control 
measures; (2) discretionary control measures; (3) growth; and (4) 
planning obligations.
---------------------------------------------------------------------------

    \29\ The draft regulatory text did not accurately reflect the 
preamble discussion which distinguished maintenance areas at the 
time of designation for the 8-hour NAAQS from those that remained 
designated nonattainment at the time of 8-hour designation. For the 
final rule, we use the time of 8-hour designations rather than the 
time the 1-hour NAAQS is revoked.
---------------------------------------------------------------------------

    b. Summary of final rule. The approach we are adopting in the final 
rule is summarized below under the individual sections discussing each 
category of area and type of control obligation.
    c. Section 51.905(a)(1): 8-hour NAAQS nonattainment/1-Hour NAAQS 
nonattainment.
    (i) Mandatory control measures. (Section VI.C.3.a.i. of proposed 
rule; see 68 FR 32820; sections 51.900(f) and 51.905(a)(1) of the draft 
and final rules.)
    (A) Background. For areas designated nonattainment for the 1-hour 
NAAQS at the time they are designated nonattainment for the 8-hour 
NAAQS, we proposed that, to the extent the area has met a mandatory SIP 
obligation under the CAA that is included as part of the approved SIP, 
the State may not modify or remove that measure except to the extent 
that it may have modified or removed that measure for purposes of the 
1-hour NAAQS (68 FR 32820). For example, if an area was classified as 
serious for the 1-hour ozone NAAQS and required to have an enhanced I/M 
program as part of its SIP, the State cannot remove the enhanced I/M 
program for that area even though it may be classified as marginal or 
moderate for the 8-hour ozone NAAQS. However, under the proposal, the 
State may modify the enhanced I/M program consistent with EPA's 
enhanced I/M regulations, just as it may have done for purposes of the 
1-hour NAAQS. (We address below when the obligation to retain such 
control measures as active control programs no longer applies, the 
geographic area in which the obligation applies, and the demonstration 
a State must make at that point to modify the SIP.)
    For control measures that the State has not yet adopted, we 
proposed that the State remains obligated to adopt and submit such 
control measures. And, once adopted into the approved SIP, the State 
may not modify or remove such measures except to the same extent that 
it could have modified or removed them for purposes of the 1-hour 
NAAQS.
    Our draft regulatory text referred to these obligations as 
``applicable requirements'' and we identified the subpart 2 mandatory 
control measures in the definitions section under ``applicable 
requirements.''
    (B) Summary of final rule. We are adopting the approach we 
proposed. (See sections 51.905(a)(1)(i)and 51.900(f) of the final 
rule.) All areas designated nonattainment for the 8-hour ozone NAAQS 
and designated nonattainment for the 1-hour ozone NAAQS at the time of 
designation for the 8-hour NAAQS remain subject to control measures 
that applied by virtue of the area's classification for the 1-hour 
NAAQS.
    As we stated in the preamble to the proposed rule (68 FR 32819), 
there are a number of provisions in the CAA that we believe are 
evidence of Congress' intent that these obligations continue to apply 
despite EPA's determination that the 1-hour NAAQS is no longer 
necessary to protect public health. For example, at the time of the 
1990 Amendments to the CAA, Congress designated and classified existing 
ozone nonattainment areas (and classified all other ozone nonattainment 
areas) as a matter of law. Congress also provided that areas could not 
remove from the SIP controls mandated by subpart 2 even after the area 
attains the NAAQS and is redesignated to attainment. At most, the State 
could move such controls to the contingency plan provisions of the SIP. 
See CAA section 175A(d). Also significant is that in 1990, Congress 
enacted a provision specifying States' obligations with respect to 
control measures for a NAAQS after EPA revised that NAAQS to be less 
stringent. In section 172(e), Congress specified that if EPA revises a 
NAAQS and makes it less stringent, EPA must promulgate regulations 
applicable to areas that have not yet attained the original NAAQS to 
require controls that are no less stringent than the controls that 
applied to areas designated nonattainment prior to such relaxation. We 
believe that, if Congress intended areas to remain subject to the same 
level of control where a NAAQS was relaxed, they also intended that 
such controls not be weakened where the NAAQS is made more stringent. 
Finally, we noted that the Supreme Court cautioned against making 
subpart 2 ``abruptly obsolete.'' For areas designated nonattainment in 
1990, Congress intended the mandatory requirements of subpart 2 to 
apply (as implemented controls or contingency measures) for a 
significant period of time. We believe if we allowed areas to remove 
those mandated controls from their SIPs it would render those 
provisions prematurely obsolete, contrary to Congressional intent. We 
adopt in full the analysis provided at 68 FR 32819, 1st and 2nd 
columns.
    The final rule also reflects, with several exceptions, the table in 
appendix B of the June proposal which identified the applicable 
requirements. The definition of ``applicable requirements'' in section 
51.900(f) of the draft regulatory text erroneously excluded some of the 
requirements included in appendix B. The requirements that weren't 
included in the proposed regulatory text definition of applicable 
requirement but are included in the definition in the final rule are:
     Enhanced (ambient) monitoring under section 
182(c)(1) of the CAA.
     Transportation controls under section 182(c)(5) 
of the CAA.
     Vehicle miles traveled provisions of section 
182(d)(1) of the CAA.
     NOX requirements under section 182(f) 
of the CAA.
    One exception in which the final rule does not reflect appendix B 
of the proposal concerns the requirement for reformulated gasoline 
(RFG). Appendix B erroneously included RFG as an applicable requirement 
under subpart 2. As discussed below under ``Comments and responses,'' 
it is not an applicable requirement under subpart 2 and is not included 
as such in section 51.900(f) of the final rule. In addition, Appendix B 
listed NSR (major source applicability and offsets) as ``applicable 
requirements'' under subpart 2. Although these would be applicable 
requirements under subpart 2 for the 8-hour standard, they would not be 
applicable requirements under subpart 2 for the 1-hour standard after 
the 1-hour standard is revoked.\30\
---------------------------------------------------------------------------

    \30\ In addition, Appendix E of the June 2, 2003 proposal treats 
1-hour NSR as an applicable requirement after the 1-hour standard is 
revoked. Under the final rule, 1-hour NSR would not be a required 
implementation plan element after the 1-hour standard is revoked. 
Instead, NSR under the 8-hour NAAQS will apply.
---------------------------------------------------------------------------

(C) Comments and responses
    Comment: Concerning the June 2, 2003 proposal, several commenters 
believed that not all control requirements required by an area's 1-hour 
classification would necessarily help achieve the 8-hour NAAQS and 
therefore opposed the proposed anti-backsliding provisions. Other 
commenters supported the proposal.
    Concerning the draft regulatory text, commenters generally 
reiterated their comments from the June 2, 2003 notice

[[Page 23973]]

in commenting on the draft regulatory text.
    Response: As we noted above and in the preamble to the proposed 
rule, we examined the CAA as a whole to discern Congressional intent 
since Congress did not specifically address anti-backsliding where EPA 
promulgated a more stringent NAAQS. After considering the ``as a matter 
of law'' designation and classification for the 1-hour NAAQS, section 
172(e), and the CAA's redesignation provisions, we believe that 
Congress intended these areas to continue to implement requirements 
that applied in the area for the 1-hour NAAQS.
    Comments: The EPA's June 2 proposal listed RFG in appendix B as an 
``applicable requirement'' for severe and above ozone nonattainment 
areas; it was also listed as an ``applicable requirement'' in the draft 
regulatory text under section 51.900(f). The EPA received a number of 
comments addressing RFG requirements. Some commenters argued that the 
program was of no environmental benefit in certain locations, and 
should not be required. One commenter suggested that where it is 
estimated that the costs per ton of VOC removal would be around $36 
million per daily ton removed or around $100,000 per annual ton 
removed, with no measurable benefit to ozone levels, that requiring use 
of RFG would be an ``absurd result'' justifying a waiver of the RFG 
requirement. One commenter argued that the rules providing for ozone 
nonattainment areas to opt-in to the RFG program should be liberalized, 
to allow additional areas to avail themselves of the benefits of RFG. 
Other commenters argued against such liberalization, on the basis that 
the fuels industry is already burdened with implementation of far-
reaching fuels regulations and does not need the additional 
difficulties that would be associated with the proliferation of RFG 
opt-ins.
    Response: The EPA has decided that it is not appropriate to list 
RFG as an ``applicable requirement'' in the final rule in section 
51.900(f). The RFG program is not adopted as a State program in SIPs, 
as are the other ``applicable requirements'' listed in today's final 
rule. Rather, RFG is required under a Federal program. It is prescribed 
in some instances by statute, and in other instances States are allowed 
to opt-in and opt-out of the program in accordance with Federal 
statutory prescriptions and EPA rules. The EPA recognizes that the 
scope and applicability of the RFG program during and after 
implementation of the new 8-hour ozone standard raises various issues 
that need further clarification. However, such clarification is more 
appropriately provided in a separate undertaking. Since Federal RFG 
does not appear on the final rule's list of ``applicable requirements'' 
in subpart 2, there is no need to respond in this rulemaking to the 
comments regarding implementation of the RFG program. Therefore, while 
not an ``applicable requirement'' under today's rules, the RFG 
requirement is nonetheless applicable under the CAA for certain areas, 
and EPA will determine in the future whether this requirement would 
change for these areas when they attain the ozone NAAQS.
    Comment: One commenter noted that the language in the draft 
regulatory text is based upon the date of revocation of the 1-hour 
ozone NAAQS, which is at least one year later than that specified in 
the proposed rule. The date of revocation is also highly uncertain 
compared to the date of designation, which is driven by the Consent 
Decree. The Draft Regulatory Text therefore conflicts with the proposed 
rule language. The commenter prefers use of the date of designation for 
these and other applicable requirements.
    Response: The regulatory text has been revised to key the 
requirement from the effective date of designation for the 8-hour 
NAAQS.
    Comment: One commenter believed there was a conflict between the 
June 2, 2003 notice and the draft regulatory text concerning the timing 
of the 1-hour NSR obligation. The draft section 51.905(a)(1) provision 
would apply for areas designated nonattainment for the 1-hour NAAQS at 
the time of revocation of the 1-hour NAAQS, but the June 2, 2003 notice 
provision would apply to areas designated nonattainment for the 1-hour 
NAAQS at the time of designation of the 8-hour NAAQS. The commenter 
recommended that the rule be based on the date of designation for the 
8-hour NAAQS.
    Response: We agree there was a conflict in the draft regulatory 
text on this matter. However, as discussed below, the final differs 
from the proposal in that after the 1-hour NAAQS is revoked, NSR under 
the 1-hour NAAQS will no longer be a required implementation plan 
element in areas that are 8-Hour NAAQS nonattainment/1-Hour NAAQS 
nonattainment. Instead, NSR under the 8-hour NAAQS will apply.
    (ii) Discretionary control measures. This discussion of 
discretionary measures includes how we plan to treat enforceable 
commitments approved into the SIP. (section VI.C.3.a.ii. of proposed 
rule, see 68 FR 32821, and section VI.C.3.a.v. of proposed rule; see 68 
FR 32822; section 51.905(d) of draft and final rules; there is no 
parallel provision in the final rule.)
    (A) Background. Many approved SIPs contain control measures that 
are not specified under subpart 2 for the area, but that the State 
chose to adopt as part of the demonstration of attainment or part of 
the ROP requirement for the 1-hour NAAQS. For these kinds of measures, 
we proposed that States retain the discretion they now have to modify 
these requirements in their SIPs. For purposes of the 1-hour NAAQS, 
States may currently revise or remove those requirements so long as 
they make a demonstration consistent with section 110(l) that such 
removal or modification would not interfere with attainment of or 
progress toward the 1-hour ozone NAAQS (or any other applicable 
requirement of the CAA).\31\ Once the 1-hour standard is revoked, for 
purposes of the 8-hour NAAQS, the same discretion to modify a SIP would 
apply except the State would need to make the demonstration required by 
section 110(l) with respect to the 8-hour NAAQS, not the 1-hour NAAQS. 
See 68 FR 32821 for an example of how this would work.
---------------------------------------------------------------------------

    \31\ For purposes of the preamble to this rulemaking, whenever 
we state that a State must make the demonstration required under 
section 110(l) to modify its SIP, we also mean that the State must 
make the required demonstration under section 193 to the extent the 
affected area is designated nonattainment and the SIP requirement 
the State is modifying was a control requirement in effect or 
required to be in effect prior to November 15, 1990.
---------------------------------------------------------------------------

    We also proposed that States remain obligated to meet enforceable 
commitments approved into a SIP to the same extent as if they were 
adopted measures (68 FR 32822). This includes enforceable commitments 
to perform a mid-course review. The only way a State may modify or 
remove such a commitment is through a SIP revision making the required 
demonstration under section 110(l).
    (B) Summary of final rule. We are adopting the approach we set 
forth in our proposed rule. A State may revise or remove discretionary 
control measures (including enforceable commitments) contained in its 
SIP for the 1-hour NAAQS so long as the State demonstrates consistent 
with section 110(l) that such removal or modification will not 
interfere with attainment of or progress toward the 8-hour ozone NAAQS 
(or any other applicable requirement of the CAA). Under the rule, 
States remain obligated to meet any SIP-approved commitment to perform 
a mid-course review. These SIP commitments generally do not bind the

[[Page 23974]]

States to take any specific action in response to the results of the 
mid-course review. The EPA anticipates that rather than using these 
reviews to ensure areas meet the 1-hour NAAQS (which will have been 
revoked), States and EPA can use these reviews to ensure progress is 
being made consistent with needs for the 8-hour NAAQS.
    Note, however, that since general provisions for modifying or 
removing control measures in a SIP are already provided in the statute 
(sections 110(l) and 193), we do not believe there is a need to have a 
duplicative provision in this final rule. Therefore, even though the 
draft regulatory text contained such a provision (section 51.905(d)), 
the final rule does not contain that provision.
(C) Comments and Responses
    Comment: Several commenters supported the proposal regarding 
discretionary control measures. Other commenters believed that States 
should not be held to commitments to submit the mid-course review 
required under their 1-hour SIP. Some commenters objected to the 
provision in draft regulatory text for allowing ``relaxations'' of the 
SIP under sections 110(l) and 193 of the CAA.
    Response: Sections 110(l) and 193 allow States to modify the 
discretionary controls in their SIPs if the provisions of those 
sections are met. While we believe it is important to prevent 
backsliding consistent with the statutory provisions, we do not believe 
it is appropriate to further restrain the discretion Congress granted 
to States in determining the appropriate mix of controls in the SIP. We 
believe that a State may revise discretionary controls approved in its 
SIP as long as it meets the criteria specified in sections 110(l) and 
193. We believe the tests provided in sections 110(l) and 193 will 
prevent the adverse effects envisioned by the commenter.
    (iii) Measures to address growth. (section VI.C.3.a.iii of proposed 
rule; see 68 FR 32821; sections 51.900(f) and 51.905(a)(1) of the draft 
and final rule.)
    (A) Background. In general, the SIP provisions in the CAA include 
one provision to address growth--nonattainment NSR. We discuss 
conformity for all areas in a later section.
    For areas that are 8-hour NAAQS nonattainment/1-hour NAAQS 
nonattainment, we proposed in the June 2, 2003 notice that the major 
source applicability cut-offs and offset ratios for nonattainment NSR 
that applied for an area's 1-hour classification continue to apply.
    (B) Summary of final rule. The final rule treats 1-hour NSR as a 
requirement that will no longer apply once the 1-hour NAAQS is revoked. 
We provide a more thorough discussion of the approach in our final rule 
and the rationale in the section below discussing 1-hour NAAQS 
obligations that no longer apply as of revocation of the 1-hour NAAQS.
    (C) Comments and responses. Comments and responses are included in 
the section below discussing 1-hour NAAQS obligations that no longer 
apply as of revocation of the 1-hour NAAQS.
    (iv) Planning SIPs.
    (A) Outstanding ROP obligation. (section VI.C.3.a.iv of proposal; 
68 FR 32822; section 51.905(a)(1) of the draft and final rules).
    (1) Background. In the June 2, 2003 proposal, we proposed that 
States remain obligated to address separately 1-hour ROP requirements 
that do not overlap with RFP obligations for the 8-hour NAAQS.\32\ 
Where outstanding ROP and RFP obligations overlap, the area need not 
submit a separate ROP plan for the 1-hour NAAQS but must show that the 
8-hour ROP plan is no less stringent than the 1-hour ROP requirement. 
For ROP provisions already adopted into the SIP, we proposed that the 
State may remove or revise control measures needed to meet the ROP 
milestone if such control measures were discretionary (i.e., not 
mandated by subpart 2 for the area's 1-hour classification), as 
discussed above, and the State makes a demonstration under section 
110(l) including a demonstration that the revision will not interfere 
with meeting the 1-hour ROP and 8-hour RFP goals.
---------------------------------------------------------------------------

    \32\ In this rulemaking, we use ``ROP'' to refer to the rate of 
progress requirement for the 1-hour NAAQS and ``RFP'' to refer to 
both the rate of progress requirement under subpart 2 and the 
reasonable further progress requirement under subpart 1 for the 8-
hour ozone NAAQS.
---------------------------------------------------------------------------

    (2) Summary of final rule. We are adopting the approach set forth 
in our proposed rule for areas that are 8-hour NAAQS nonattainment/1-
hour NAAQS nonattainment. States remain obligated to meet the CAA-
mandated ROP emission reduction targets that applied for the 1-hour 
NAAQS, but discretionary measures adopted to meet those targets may be 
modified, if the State makes the necessary showing under section 
110(l).
    In addition, we are providing further clarification regarding how 
this obligation applies. Areas that have an outstanding obligation for 
an approved 1-hour ROP SIP for one or more of the ROP periods (e.g., 
1999-2002, 2002-2005, 2005-2007) must still develop and submit to EPA 
(if they have not already done so) all outstanding 1-hour ROP plans. 
Where a 1-hour ROP obligation overlaps with an 8-hour RFP requirement, 
the State's 8-hour RFP measures can be used to satisfy the 1-hour ROP 
obligation.
    The State may choose to show that both the 8-hour and 1-hour ROP 
obligations are met through a single 8-hour plan submittal. To prevent 
backsliding, the State must ensure that the 8-hour RFP emission plan is 
at least as stringent as the 1-hour ROP emission target, for the year 
in which 1-hour ROP must be met. The State may do this by first 
establishing an RFP emission target for the entire 8-hour ozone 
nonattainment area, for the 1-hour ROP target year. If the 8-hour RFP 
emission target for the 8-hour area for the same period is more 
stringent than the 1-hour ROP emission target for the 1-hour area 
(assuming the 8-hour area includes the entire 1-hour area), the State 
is not obligated to submit a separate 1-hour ROP plan, but can rely 
solely on the 8-hour RFP plan and emission target to demonstrate that 
the 1-hour target will be met. However, the State must ensure that the 
emission target will be met for the same period as for 1-hour ROP 
(e.g., 2003-2005). The State may rely on any control measure to meet 
both ROP for the 1-hour NAAQS and RFP for the 8-hour NAAQS. Appendix A 
below provides an example of how this might work.
    In the June 2, 2003 proposal (68 FR 32835), we proposed that the 
Agency's Clean Data Policy \33\ would remain effective under the 8-hour 
ozone NAAQS, and we therefore intend to apply this policy in 
implementing this final rule for areas that achieve the 8-hour NAAQS. 
Thus, if an area attains the 8-hour ozone NAAQS, under the Agency's 
``Clean Data Policy,'' EPA may waive the 1-hour RFP obligation for the 
area based on a determination that the area has attained the 8-hour 
NAAQS. Under that policy, the State will not be subject to the 1-hour 
RFP requirement for so long as the area remains in attainment with the 
8-hour NAAQS. (The EPA will address the applicability of the Clean Data 
Policy for 8-hour ozone nonattainment areas in Phase 2 of the 
implementation rule.)
---------------------------------------------------------------------------

    \33\ Op cit.
---------------------------------------------------------------------------

    We believe that there is ambiguity in the statute regarding whether 
areas should remain subject to the requirement to submit planning SIPs, 
such as the 1-hour ROP plans. Unlike control obligations, we do not 
believe there is as strong an argument that Congress intended areas to 
continue to

[[Page 23975]]

submit planning SIPs for a NAAQS that EPA has determined is no longer 
necessary to protect public health. Section 172(e), which applies when 
EPA relaxes a NAAQS, only requires EPA to ensure that control measures 
are no less stringent than they were for the more stringent NAAQS that 
has been replaced. It does not indicate a Congressional intent that 
areas remain obligated to plan for and meet a NAAQS as it existed 
before it was revised. However, both attainment demonstrations and ROP 
plans result in the adoption of control obligations. And, if EPA 
determined that these planning requirements did not apply at all, areas 
currently designated nonattainment for the 1-hour NAAQS that have not 
met these obligations might be subject to less stringent controls than 
would have otherwise applied. Thus, in considering how to treat this 
obligation, we balanced the need to ensure the same level of control 
with the difficulties associated with meeting this obligation.
    For purposes of ROP, the exercise of calculating the reductions 
necessary to meet ROP is relatively simple. Moreover, as provided 
above, even if the State must calculate ROP separately for the 1-hour 
and 8-hour NAAQS, it may still rely on one or more of the same control 
measures to meet both those obligations. Additionally, we believe that 
most of the areas with an outstanding 1-hour ROP obligation will be 
able to demonstrate that the 8-hour RFP targets for the same time 
period will be more stringent and thus will not be required to prepare 
a separate 1-hour ROP plan. Finally, we note that States have already 
submitted and, EPA has already approved 1-hour ROP plans for most 1-
hour nonattainment areas. Thus, the anti-backsliding provisions 
regarding the continued obligation to adopt and submit 1-hour ROP plans 
will affect only a handful of areas. For these reasons, we are adopting 
a regulation that requires areas that are 8-hour NAAQS nonattainment/1-
hour NAAQS nonattainment to continue to adopt and achieve the level of 
ROP reductions mandated by Congress under the CAA for that NAAQS.
    (3) Comments and responses
    Comments on June 2, 2003 Proposal: Few commenters submitted 
comments on the portion of the proposed rule discussing the anti-
backsliding requirements applicable to 1-hour ROP. Several commenters 
generally opposed any continued planning obligations under the 1-hour 
NAAQS, but did not raise specific concerns with respect to ROP. 
Similarly, a number of other commenters opposed revocation of the 1-
hour NAAQS and urged retention of all 1-hour planning and control 
obligations; but again, these commenters did not raise concerns 
specific to the proposed anti-backsliding approach for ROP.
    One commenter, addressing section 51.905(a)(1)(iii) of the draft 
regulatory text, argued that States should have the ability to modify 
ROP measures if it can be demonstrated that they are not needed for 
purposes of meeting requirements under the 8-hour NAAQS or if measures 
are no longer appropriate due to updated technical information 
regarding emissions inventory and control strategy effectiveness. 
Another commenter objected to retaining the 1-hour ROP requirement, 
primarily because areas recently reclassified to a higher 
classification would have a continuing obligation for ROP even if they 
were not required to develop an RFP plan under the 8-hour NAAQS. 
Another commenter believed the 1-hour ROP requirement should only be 
required where it is demonstrated to be needed for attainment of the 8-
hour NAAQS.
    Response: As provided above, we believe Congress intended areas to 
continue to have control measures no less stringent than those that 
applied for the 1-hour NAAQS. Because the ROP obligation results in 
control obligations, we believe areas should remain obligated to adopt 
outstanding ROP obligations to ensure that the ROP milestones are met. 
If a State believes adopted controls are not the best fit for the 8-
hour NAAQS, the State retains full discretion to revise those controls 
so long as the revision doesn't interfere with the ROP milestones.
    Without this provision, an area with an unmet obligation to submit 
and implement a ROP plan under the 1-hour NAAQS could experience 
backsliding by being released from the obligation to have controls in 
place that achieve a specified level of emissions reductions during the 
interim period prior to implementation of the SIP required for the 8-
hour NAAQS. In other words, if the 1-hour NAAQS were not revoked, the 
area would have been required to continue to ensure emissions would be 
reduced by specified levels in specific timeframes. If the final rule 
contained no provision comparable to section 51.905(a)(1)(i), 
achievement of those emissions reductions would almost certainly be 
delayed. Because we are transitioning to a more stringent and 
protective air quality NAAQS. We see no reason why there should be 
provisions that would provide less protection to public health.
    (B) Unmet attainment demonstration obligations (section VI.C.3.a.iv 
of proposal; see 68 FR 32822; section 51.905(a)(1)(ii) of the draft and 
final rules)
    (1) Background. Most areas designated nonattainment for the 1-hour 
ozone NAAQS have fully approved attainment demonstrations for the 1-
hour NAAQS. Because there are so few areas without approved attainment 
demonstrations, in the proposed rule we identified the two types of 
situations of which we were aware and solicited comment on how to 
handle those situations. First, there are a few areas that do not have 
a fully approved attainment demonstration because the area has not 
acted in accordance with the timelines provided under the CAA. The 
second situation is an area which has a future obligation to submit an 
attainment demonstration. In general, these are areas that, over the 
past several years, have been reclassified (i.e., ``bumped up'') to a 
higher classification. In the preamble to the proposal, we discussed 
the policy reasons that would support retention of the obligation to 
submit an attainment demonstration and the policy reasons that would 
counsel against retention of that obligation (68 FR 32822). For both 
these groups of areas, we solicited comment on whether to retain the 
obligation to develop a 1-hour attainment demonstration. In addition, 
we solicited comment on two alternatives that would address many of the 
policy concerns we noted.
    Alternative 1 would require that areas with a current or past due 
obligation to submit a new or revised attainment demonstration instead 
be required to submit a SIP revision that would obtain an advance 
increment of local emissions reductions toward attainment of the 8-hour 
ozone NAAQS within a specified, short-term timeframe; 5 percent and 10 
percent were suggested possibilities for the increment. Under 
Alternative 2, areas with a current or past due obligation to submit a 
1-hour attainment demonstration would be required to submit their 8-
hour ozone attainment demonstration early in lieu of being required to 
submit a 1-hour attainment demonstration. The draft regulatory text was 
developed using the first alternative, and used a 10 percent increment.
    (2) Summary of final rule. In the final rule, we are allowing the 
States to choose among three options that are tailored after the 
approaches addressed in the proposed rule. Thus, rather than 
establishing one mandatory approach, we are adopting a rule that will 
allow

[[Page 23976]]

States to choose any one of the following three options:
     Option 1. Submit a 1-hour attainment 
demonstration.
     Option 2. Submit, no later than 1 year after the 
effective date of the 8-hour designations, an early increment of 
progress plan toward the 8-hour NAAQS which provides:
     A 5 percent increment of reduction from the 2002 
emissions baseline (NOX and/or VOC). The control measures 
for achieving this increment must be in addition to measures (or 
enforceable commitments to measures) in the SIP as of the effective 
date of designation and in addition to national or regional measures. 
(The State can take credit for this increment of reduction toward its 
RFP requirement under the 8-hour NAAQS.)
     For achievement of the emissions reductions 
within 2 years after submittal (i.e., 3 years after designation).
     Option 3. Submit an early 8-hour ozone 
attainment demonstration SIP 1 year after the effective date of 
designation for the 8-hour NAAQS that:
     Demonstrates attainment of the 8-hour NAAQS by 
the area's attainment date,
     Provides for 8-hour RFP consistent with the 
area's classification out to the area's attainment date, and
     Ensures that the first segment of RFP \34\ 
between the end of 2002 and the end of 2008 is achieved early--by the 
end of 2007.
---------------------------------------------------------------------------

    \34\ The amount of which will depend on the ROP option in the 
final rule and the classification of the area.
---------------------------------------------------------------------------

    With respect to Option 2, the final rule specifies a 2002 baseline 
year for calculating the early increment of progress whereas the draft 
regulatory text did not provide a specific baseline year.
    As noted above in the ROP section, we believe the statute is 
ambiguous regarding the need for States to address planning for a NAAQS 
no longer needed to protect public health. However, since these 
planning SIPs result in the adoption of control measures, which we 
believe Congress intended be no less stringent, we examined what 
approaches would ensure controls are adopted and implemented without 
unnecessarily obligating States to plan for a NAAQS not needed to 
protect public health.
    Unlike planning for ROP, preparing an attainment demonstration 
involves complex modeling and analyses that can be resource intensive 
both in terms of workload and cost. We don't believe it is appropriate 
or necessary to mandate that States perform the attainment 
demonstration for a NAAQS that is not needed to protect public health. 
But we also do not believe it is appropriate to waive in total this 
obligation in light of the need to ensure there is no delay in 
achieving emissions reductions to protect public health. We are 
adopting an approach that provides States with options because it 
provides maximum flexibility to States that have outstanding attainment 
demonstration obligations while continuing to obtain in a timely 
fashion many or all of the emissions reductions that should occur under 
those obligations, effecting an orderly transition to planning under 
the 8-hour NAAQS. In addition, we do not believe it is equitable to 
relieve these areas of this obligation where other areas have already 
adopted controls to meet these obligations and will not be able to 
modify or remove such controls unless the State can demonstrate that 
such action is consistent with section 110(l).
    Thus, in balancing Congressional intent to ensure no backsliding, 
equitable treatment of all areas, the need for areas to begin planning 
for the 8-hour NAAQS and the limited planning resources that States 
have available, we believe the best approach is to provide States with 
several alternatives, each of which will achieve emissions reductions 
on a timeframe similar to when they would have been achieved for the 1-
hour NAAQS through a 1-hour attainment demonstration SIP. The State may 
choose the option that is least burdensome in light of activities 
already performed. For example, States with a 1-hour attainment 
demonstration that is past due or is due in the next several months may 
have already made significant progress in developing a 1-hour 
attainment demonstration SIP. Thus, these States may choose the first 
option. We are aware that one or more States have already begun the 
process of developing 8-hour attainment demonstrations for some 1-hour 
nonattainment areas. These States may choose to submit an early 8-hour 
attainment demonstration SIP. Other areas, which have not yet made 
significant progress on 1-hour or 8-hour attainment planning, may wish 
to reserve more time for the attainment demonstration process, which 
can involve complex modeling, and thus choose the third option--to 
achieve an early increment of progress.
    For the second option available to States, we chose 5--rather than 
10--percent as the amount of reduction. Under this option, States must 
achieve the 5 percent emission reduction from local controls (not 
currently required by the SIP) and within 3 years of designation for 
the 8-hour NAAQS. In light of the quick timeframe in which to achieve 
the reductions following designations and the limitation that such 
reductions cannot be from regional or national controls or from 
measures already in the SIP, we concluded that 10 percent was unduly 
burdensome. The States that choose this option will need to identify 
and adopt appropriate controls within a 1-year timeframe and require 
sources to implement the controls within a short time thereafter. These 
limitations will restrict the control choices available to States. In 
addition, because of the limited timeframe for adoption and submission 
of the controls to EPA, we do not believe it is reasonable to require 
the State to obtain a level of reduction that would force the States to 
concentrate its resources on the early ROP reduction rather than on an 
8-hour attainment plan. However, because the State will not be able to 
rely on national or regional controls, we are confident that the 5 
percent requirement will achieve the anti-backsliding goal.
    Finally, as with the 1-hour ROP requirement, we note that EPA may 
waive the 1-hour attainment demonstration requirement for areas based 
on a determination that the area has attained the 8-hour NAAQS. The 
EPA's Clean Data Policy \35\ provides that if EPA has determined that 
an area has attained the 1-hour NAAQS, it will not be obligated to 
submit a 1-hour attainment demonstration for so long as it maintains 
the 1-hour NAAQS. Thus, extending this policy to the 8-hour NAAQS, if 
EPA determines that an area has attained the 8-hour ozone NAAQS before 
the time the area is obligated to make a submission under this portion 
of EPA's 8-hour implementation regulations, EPA would waive this 
requirement for so long as the area remains in attainment with the 8-
hour NAAQS. (The EPA will address the applicability of the Clean Data 
Policy for 8-hour ozone nonattainment areas in Phase 2 of the 
implementation rule.)
---------------------------------------------------------------------------

    \35\ Memorandum of May 10, 1995, ``RFP, Attainment 
Demonstration, and Related Requirements for Ozone Nonattainment 
Areas Meeting the Ozone National Ambient Air Quality Standard,'' 
from John S. Seitz, Director, Office of Air Quality Planning and 
Standards. Available at: http://www.epa.gov/ttn/oarpg/t1/memoranda/clean15.pdf.
---------------------------------------------------------------------------

    (3) Comments and responses.
    Comment: Several commenters advocated retaining the planning 
obligations under the 1-hour NAAQS, expressing the belief that momentum 
will be lost in implementing controls if these obligations are not 
retained. In general, most of these commenters also

[[Page 23977]]

opposed revocation of the 1-hour NAAQS and believed Congress intended 
the 1-hour NAAQS to be planned for and met. Some commenters opposed 
retaining the attainment demonstration requirements under the 1-hour 
NAAQS after the NAAQS is revoked on the basis that State resources are 
limited and should be focused on developing plans for implementing the 
8-hour rather than the 1-hour NAAQS. A few commenters favored the 
alternative of requiring an early plan with an advance increment of 
emissions reductions toward progress of the 8-hour NAAQS in lieu of the 
attainment demonstration SIP revision. A few other commenters favored 
the alternative of requiring States to submit an early attainment 
demonstration SIP for the 8-hour NAAQS.
    Only one commenter believed that 10 percent was the appropriate 
amount under Alternative 1 for an advance increment of progress; 
several others opposed 10 percent, claiming that it appeared to be 
punitive, that there was no technical support for that amount, and that 
it may be more than what was needed for attainment of the 8-hour NAAQS.
    Some commenters recommended that exceptions be made for any area 
that made good faith efforts to develop and submit its plan, such as 
those with a submitted and approved plan that may have been challenged 
and overturned by a court.
    Response: We have designed the final rule such that an area without 
an approved attainment demonstration or ROP plan would still be 
required to submit and implement a ROP plan and an attainment 
demonstration or substitute plan as required for the 1-hour NAAQS. We 
believe this approach will ensure there are no delays in achieving 
emissions reductions as we transition to the more stringent 8-hour 
ozone NAAQS.
    We believe that areas that have not met their planning obligations 
under the 1-hour NAAQS--if relieved of that obligation after the 1-hour 
NAAQS is revoked--would provide emissions reductions on a more 
protracted time schedule than areas that had met their 1-hour NAAQS 
planning obligations. For example, an area that is classified severe-15 
for the 1-hour NAAQS would have to obtain RFP reductions and any 
additional reductions needed for attainment by the end of 2005, whereas 
if that same area is moderate under the 8-hour NAAQS, it would not be 
required to obtain reductions under the RFP provisions until 2008 and 
additional reductions for attainment by some time in 2009. We believe 
that the provisions of the final rule--by offering three alternative 
means of meeting the 1-hour attainment demonstration obligation--allow 
sufficient flexibility for a State in these circumstances to choose the 
most appropriate means to achieve these reductions in the time intended 
by Congress.
    d. Section 51.905(a)(2): 8-hour NAAQS Nonattainment/1-hour NAAQS 
Maintenance
    In the June 2003 proposal, we discussed the requirements for areas 
designated as attainment for the 1-hour NAAQS with a maintenance plan 
at the time of designation for the 8-hour NAAQS in the same sections 
discussing the requirements for areas designated nonattainment for the 
1-hour NAAQS at the time of 8-hour designations. However, in the draft 
regulatory provisions, we created a separate subparagraph addressing 
these areas. Below, we indicate briefly where the obligations for these 
areas, i.e., maintenance areas at the time of designation, are the same 
as for areas designated nonattainment for the 1-hour NAAQS at the time 
of 8-hour designations. We discuss in more detail where the obligations 
differ.
    (i) Mandatory Control Measures. (section VI.C.3.a.i. of proposed 
rule; see 68 FR 32821; sections 51.900(f) and 51.905(a)(2) of draft and 
final rules).
    (A) Background. In the June 2003 proposal, we proposed that all 
areas designated nonattainment for the 8-hour NAAQS and that were 
nonattainment or maintenance for the 1-hour NAAQS at the time of 8-hour 
designations would be required to continue to implement mandatory 
measures adopted into the approved SIP. We did not distinguish between 
areas designated nonattainment for the 1-hour NAAQS at the time of 
designation for the 8-hour NAAQS and areas that are maintenance for the 
1-hour NAAQS at the time of designation for the 8-hour NAAQS. However, 
in the draft regulatory text, we created a separate provision for 
maintenance areas because these areas do not have an outstanding 
obligation to adopt mandatory control obligations for the 1-hour 
NAAQS.\36\ Thus, the draft regulatory provision for maintenance areas 
did not address the future adoption of controls; it simply provided 
that these areas would be required to continue to implement the 
applicable requirements (as defined in the regulatory text) in the 
approved SIP.
---------------------------------------------------------------------------

    \36\ In order to redesignate these areas to attainment, EPA had 
to determine these areas had met all obligations under part D. See 
CAA section 107(d)(3)(E).
---------------------------------------------------------------------------

    We also provided in the June 2003 proposal and the draft regulatory 
text that if a maintenance area had previously shifted a mandatory 
control measure to the contingency provisions, the area would not be 
required to begin implementation of that measure based on the 8-hour 
nonattainment designation. However, the measure would need to remain as 
a contingency measure for the area and could not be removed from the 
SIP.
    (B) Final Rule. We are adopting the approach we took in the 
proposal and the draft regulatory text. Areas that are maintenance for 
the 1-hour NAAQS at the time of 8-hour designations and are designated 
nonattainment for the 8-hour NAAQS, must continue to implement 
mandatory control requirements (i.e., ``applicable requirements'') that 
have been approved into the SIP. However, since maintenance areas do 
not have any outstanding obligation to adopt mandatory control measures 
for the 1-hour NAAQS, the provision only addresses implementation, not 
adoption. In addition, this section recognizes that maintenance areas 
had the flexibility to move mandatory controls to the contingency 
measures portion of their maintenance plan. The area would not be 
required to implement these measures unless it is required to do so for 
the area's classification for the 8-hour NAAQS. However, the measures 
would need to remain as contingency measures and could not be removed 
from the SIP.
    We are adopting the requirement that 1-hour maintenance areas are 
required to continue to implement mandatory controls for the same 
reasons we provided with respect to 8-hour NAAQS nonattainment/1-hour 
NAAQS nonattainment areas above. With respect to mandatory measures 
that the State has moved to the contingency portion of the maintenance 
plan, we do not believe that Congress intended to require areas to 
begin implementing such measures again based on the promulgation of a 
revised NAAQS unless required based on the area's classification for 
the revised NAAQS. These areas have fully complied with the process 
that Congress established--attainment of the (then-existing) NAAQS and 
redesignation to attainment for that NAAQS based on a plan 
demonstrating that the area will maintain the NAAQS. While we believe 
these areas should not ``backslide'' from existing control levels, we 
do not believe that for purposes of the 8-hour NAAQS they should be 
required to begin implementing once more measures that the State has 
chosen to place in the contingency measures portion of the SIP.
    (ii) Discretionary Control Measures. (Section VI.C.3.a.ii. of 
proposed rule,

[[Page 23978]]

see 68 FR 32821, Section 51.905(a)(2) of draft regulatory text; there 
is no parallel provision in the final rule.)
    (A) Background. The June 2, 2003 proposal did not discuss the 
requirements for these areas independent of all areas that were 
designated nonattainment for the 1-hour NAAQS on or after November 15, 
1990. The draft regulatory text (section 51.905(a)(2)), however, did 
provide for this situation separately but did not directly address 
discretionary measures.
    (B) Summary of Final Rule. As with discretionary control measures 
for 8-hour NAAQS nonattainment/1-hour NAAQS nonattainment areas, 1-hour 
NAAQS maintenance/8-hour NAAQS nonattainment areas will retain the 
discretion to modify any discretionary control measures upon a 
demonstration under section 110(l). We are not promulgating regulatory 
text because, as described above, sections 110(l) and 193 of the CAA 
govern such SIP revisions.
    (iii) Measures to address growth. (Section VI.C.3.a.iii of proposed 
rule; see 68 FR 32821; sections 51.900(f) and 51.905(a)(1) of the draft 
and final rules)
    (A) Background. In the proposal, we recognized that 1-hour 
maintenance areas generally are subject to the prevention of 
significant deterioration (PSD) program and are no longer implementing 
the nonattainment NSR program for their previous 1-hour ozone 
designation and classification.\37\ For areas where the NSR program no 
longer applies under the SIP, we proposed that the areas would not need 
to revert back to the NSR program they had for purposes of the 1-hour 
NAAQS. The proposal provided examples of how this would work (68 FR 
32821).
---------------------------------------------------------------------------

    \37\ If an area located in the Ozone Transport Region was 
redesignated to attainment, section 184(b)(2) of the CAA required it 
to retain a nonattainment NSR program. In addition, it is possible 
that one or more areas still has a nonattainment NSR program in 
place because of the way the State wrote the SIP.
---------------------------------------------------------------------------

    (B) Summary of final rule. We are adopting the approach we proposed 
but our rationale relies on the final rule's provision that NSR under 
the 1-hour standard will no longer apply as of revocation of the 1-hour 
standard. If an area has been redesignated to attainment for the 1-hour 
NAAQS as of the effective date of the 8-hour nonattainment designation 
and is no longer required to implement a nonattainment NSR program, the 
area will not be required to revert back to the program it had for 
purposes of the 1-hour ozone NAAQS. As noted elsewhere, NSR offset 
ratios and source applicability provisions under the 1-hour standard 
are not being defined as ``applicable requirements'' after the 1-hour 
standard is revoked.
    As provided in more detail below for 8-hour NAAQS nonattainment/1-
hour NAAQS nonattainment areas, we have determined that 1-hour NAAQS 
NSR should not continue to apply once the 1-hour NAAQS is revoked for 
those areas. It would not be reasonable to require these areas to begin 
those 1-hour programs again for the 1-year between designation for the 
8-hour NAAQS and revocation of the 1-hour standard. Moreover, Congress 
did not intend the nonattainment NSR program to continue to apply to 
most areas once they are redesignated to attainment. Rather, such areas 
are subject to the PSD program. For an area that has met the clean air 
goals for the 1-hour NAAQS, we see no reason to require such area to 
revert back to its 1-hour NSR program. These areas will be required to 
implement the nonattainment NSR program that applies based on their 
classification for the 8-hour ozone NAAQS.
    (iv) Planning SIPs. (Section VI.C.3.a.iV. of proposed rule, see 68 
FR 32822; no specific provision in draft regulatory text or final 
rule.)
    (A) Background. In the June 2003 proposal, we did not discuss 
maintenance areas separate from 8-hour NAAQS nonattainment/1-hour NAAQS 
nonattainment areas. However, the preamble discussion focused on areas 
with an outstanding obligation to submit a 1-hour ROP or attainment 
plan and the obligation to ensure that the ROP percentage reduction 
obligations in the approved SIP are achieved. Maintenance areas for the 
1-hour NAAQS do not have an outstanding obligation to submit ROP or 
attainment plans for the 1-hour NAAQS. Thus, the draft regulatory text 
did not include language similar to that in 51.905(a)(ii) and (iii) for 
maintenance areas. The draft regulatory text did reflect ROP as an 
applicable requirement for maintenance areas, indicating that these 
areas must ensure that any SIP revision does not interfere with an 
approved ROP milestone.
    (B) Summary of final rule. We are adopting the approach taken in 
the draft regulatory text. In redesignating an area to attainment, EPA 
must conclude that the area has met all requirements applicable under 
section 110 and part D. Thus, maintenance areas do not have continuing 
progress and attainment demonstration requirements, and the final rule 
does not establish requirements for maintenance areas related to 
outstanding attainment demonstration and ROP plans. The final rule does 
identify the ROP percent reduction requirement as an applicable 
requirement. However, we note that the ROP periods for areas 
redesignated to attainment for the 1-hour NAAQS have already passed and 
thus any revision to the SIP should not affect ROP reductions for the 
periods required for the 1-hour NAAQS.
    (C) Comments and responses.
    Comment: One commenter believed that 1-hour maintenance areas 
designated nonattainment under the 8-hour NAAQS should not have to 
submit updates to the 1-hour maintenance plan, since they will be 
developing 8-hour attainment plans that will subsume the requirements 
of the maintenance plan previously in effect.
    Response: The rule provides that after the 1-hour ozone NAAQS is 
revoked, areas are relieved of responsibilities to submit updates to 
their 1-hour maintenance plans. The State may submit a revision to the 
SIP to remove the provisions that require the update to the maintenance 
plan.
    Comment: One commenter noted that draft Section 51.905(a)(2) would 
limit shifting of an applicable requirement to the contingency measure 
portion of an area's maintenance plan. Under the proposal, a State may 
only make such a shift prior to the revocation of the 1-hour NAAQS; 
States may only make subsequent shifts by satisfying the requirements 
of section 110(l) of the CAA. The commenter believes that this 
criterion for shifting measures to the maintenance plan is more 
stringent and burdensome than the requirements in section 175A of the 
CAA for maintenance plans. In the alternative, the commenter recommends 
that in lieu of the showing required by Section 110(l), that States, 
instead, be allowed to substitute a control measure with equivalent 
emissions reductions for the measures they propose to remove from their 
plan.
    Response: We agree with the commenter that section 51.905(a)(2) 
will limit the authority of an area that was maintenance for the 1-hour 
standard at the time of designation as nonattainment for the 8-hour 
standard. However, we disagree with the commenter regarding the 
statutory provisions that apply for purposes of SIP revisions. The 
commenter is incorrect that section 110(l) does not apply to revisions 
to maintenance plans. Prior to being designated nonattainment for the 
8-hour NAAQS, such an area could move adopted measures to the 
contingency measures portion of the maintenance plan based on a 
demonstration under section 110(l) that such a revision would not 
interfere with attainment, maintenance or any other applicable 
requirement of the CAA. Our

[[Page 23979]]

rule provides that upon designation as nonattainment for the 8-hour 
NAAQS, a 1-hour maintenance area will not be able to shift adopted 
mandatory controls (i.e., those identified as ``applicable 
requirements'' in the regulation) to contingency measures as those 
obligations are now defined as ``applicable requirements.'' Once the 
area is redesignated to attainment for the 8-hour NAAQS, such 
obligations will no longer be defined as ``applicable requirements'' 
and the State can move them to contingency measures based on a 
demonstration that to do so would not interfere with attainment or 
maintenance of the 8-hour NAAQS or any other applicable requirement of 
the CAA. For adopted control measures that are not identified as 
``applicable requirements'' in the regulation, the State will continue 
to have the same authority it currently has for shifting adopted 
controls to contingency measures, based on a demonstration under 
section 110(l).
    Comment: One commenter noted that in section 51.905(a)(2), the 
clause ``* * * except to the extent required under its 8-hour 
obligations * * *'' could be interpreted to imply that contingency 
measures in the 1-hour maintenance plan become 8-hour measures by 
default. The commenter suggested language to avoid an incorrect 
interpretation.
    Response: The final rule reflects this recommended language change 
with some slight modifications.
    e. Section 51.905(a)(3): 8-Hour NAAQS Attainment/1-Hour NAAQS 
Nonattainment
    (i) Mandatory control obligations. (Section VI.C.3.b. of proposal, 
see 68 FR 32823; section 51.905(a)(3)(i) of the draft and final rule)
    (A) Background. The proposal noted that the issue of what 
obligation remains with respect to mandatory control measures approved 
into the SIP or required under the CAA is based on the CAA's 
requirements for maintenance plans. We proposed that if EPA determined 
that these areas were required to develop maintenance plans pursuant to 
section 175A, then they would need to keep (or to adopt and then keep) 
those control measures in the SIP, though they could shift them to 
contingency measures.
    For an area that was never redesignated to attainment for the 1-
hour standard and never had a section 175A maintenance plan, we 
proposed that if the area wants to revise any part of its current 1-
hour SIP, the area must first adopt and submit a maintenance plan 
consistent with section 110(a)(1) (discussed below). We proposed that 
these obligations would remain in place but in a later section of the 
preamble proposed options as to when this obligation would no longer 
apply.\38\
---------------------------------------------------------------------------

    \38\ These two options were: (1) When the area attains the 1-
hour NAAQS, or (2) when the area attains the 8-hour NAAQS.
---------------------------------------------------------------------------

    (B) Summary of final rule.
    We are adopting an approach consistent with our proposed rule. As 
we discuss later in this preamble, we have determined that mandatory 
control obligations will no longer apply once an area attains the 8-
hour NAAQS. Thus, because these areas are attaining the 8-hour NAAQS, 
the State may request that obligations under the applicable 
requirements of section 51.900(f) be shifted to contingency measures 
once the 1-hour NAAQS is revoked, consistent with sections 110(l) and 
193 of the CAA. However, the State cannot remove the obligations from 
the SIP.
    Because these areas are in attainment with the health-based NAAQS, 
we believe that Congress--as with areas redesignated from nonattainment 
to attainment--did not intend the areas to retain these controls as 
implemented measures if the area can demonstrate maintenance without 
the controls. As with areas redesignated to attainment, the rule 
provides that the State cannot remove the measures from the SIP, but 
rather may move them to the contingency measures portion of the SIP. We 
did not receive comments directly addressing mandatory control 
obligations for this category of areas outside the context of 
maintenance plans for these areas discussed below.
    (ii) Discretionary control obligations. (Section VI.C.3.b.iii. of 
proposal; 68 FR 32823; section 51.905(d) of draft regulatory text; no 
parallel provision in final rule.)
    Areas designated nonattainment for the 1-hour NAAQS that are 
designated attainment for the 8-hour ozone NAAQS will retain the 
ability to modify any discretionary controls upon a demonstration under 
section 110(l). However, such controls must remain in the SIP as 
contingency measures. We are not promulgating regulatory text because, 
as described above, sections 110(l) and 193 of the CAA govern such SIP 
revisions. As with mandatory measures, we look to the maintenance plan 
provision of section 175A to see what Congress' intent may have been 
for these areas. Because these areas were nonattainment for the 1-hour 
NAAQS, we believe Congress intended them to retain the measures in the 
SIP, but could shift them to contingency measures if the area 
demonstrates it will maintain the 8-hour NAAQS if the measure is no 
longer implemented. We did receive comments directly addressing 
discretionary control obligations for this category of areas outside 
the context of maintenance plans for these areas discussed below.
    (iii) Measures to address growth. (Section VI.C.3.b.i. of proposal; 
68 FR 32823; no provision in draft or final rule.)
    (A) Background. The proposal explained that NSR applies only in 
nonattainment areas.\39\ Since these areas would be designated 
attainment for the 8-hour NAAQS--the only ozone NAAQS that exists for 
the area once the 1-hour NAAQS is revoked--they would be subject to 
PSD, not NSR, once the 1-hour NAAQS is revoked.
---------------------------------------------------------------------------

    \39\ If an area located in the Ozone Transport Region was 
redesignated to attainment, section 184(b)(2) of the CAA required it 
to retain a nonattainment NSR program. In addition, it is possible 
that one or more areas still has a nonattainment NSR program in 
place because of the way the State wrote the SIP.
---------------------------------------------------------------------------

    (B) Summary of final rule. We are adopting the approach we set 
forth in our proposed rule for areas designated attainment for the 8-
hour NAAQS and designated nonattainment for the 1-hour NAAQS at the 
time of designation for the 8-hour NAAQS. After the 1-hour NAAQS is 
revoked, the CAA requires such areas to comply with PSD, not NSR. (The 
States may need to modify their SIPs so that it provides for PSD rather 
than NSR in such areas.) We do not see a basis for mandating that such 
areas retain a nonattainment NSR program and do not believe that 
Congress intended such a result. As an initial matter, once the 1-hour 
NAAQS is revoked, these areas are meeting the only ozone NAAQS that is 
in place. Congress specified that PSD shall apply in areas not 
designated nonattainment (section 161 of the CAA). In addition, as 
provided in more detail below for 8-hour NAAQS nonattainment/1-hour 
NAAQS nonattainment areas, we have determined that 1-hour NAAQS NSR 
should not continue to apply once the 1-hour NAAQS is revoked for those 
areas.
    Note that for these areas, the NSR provisions may be removed from 
the SIP and need not be shifted to contingency measures.\40\ We have 
never interpreted section 175A of the CAA to mandate that nonattainment 
NSR be retained as a contingency measure in the SIP after an area is 
redesignated from nonattainment to attainment because we do not 
interpret NSR to be a control

[[Page 23980]]

measure. (See, e.g., May 12, 2003; 68 FR 25436.)
---------------------------------------------------------------------------

    \40\ Memorandum from Mary Nichols to Regional Air Division 
Directors dated October 14, 1994, entitled ``Part D New Source 
Review (part D NSR) Requirements for Areas Requesting Redesignation 
to Attainment.''
---------------------------------------------------------------------------

    (C) Comments and responses.
    Comment: Some commenters believed that the 1-hour NAAQS should 
remain in effect, and therefore NSR would continue to apply until the 
area attains the 1-hour NAAQS and is redesignated to attainment for 
that NAAQS regardless of the area's status for the 8-hour NAAQS. Other 
commenters generally agreed with the proposal.
    Response: We address the broader legal and policy issues regarding 
revocation of the 1-hour NAAQS in the revocation section of this rule.
    (iv) Planning SIPs. (Section VI.C.3.b(ii) of proposed rule; see 68 
FR 32823; section 51.905(a)(3)(ii) of draft and final rule.)
    (A) Background. In the June 2, 2003 proposed rule, we proposed that 
any outstanding SIP planning requirements (ROP plans and attainment 
demonstrations) that applied for purposes of the 1-hour NAAQS would not 
continue to apply to areas designated attainment for the 8-hour NAAQS 
for as long as they continue to maintain the 8-hour NAAQS. If such an 
area violates the 8-hour NAAQS prior to having an approved maintenance 
plan meeting the requirements of section 110(a)(1) the obligation to 
have a 1-hour attainment demonstration and ROP plan would once again 
apply in the same manner that they apply for 8-hour NAAQS 
nonattainment/1-hour NAAQS nonattainment areas.
    The draft regulatory text (section 51.905(a)(3)) contained specific 
provisions addressing the obligation for an area designated attainment 
for the 8-hour NAAQS that subsequently violates the 8-hour NAAQS prior 
to having an approved maintenance plan under section 110(a)(1). If the 
area was required to and does not have an approved attainment 
demonstration or ROP plan for the 1-hour NAAQS, the State would be 
required to submit a plan providing for a 10 percent emission reduction 
as a substitute for the attainment demonstration and to adopt and 
submit any outstanding ROP emission reductions.
    (B) Summary of final rule. We are adopting our proposal with some 
modification. As an initial matter, section 51.905(a)(3) now only 
addresses 8-hour NAAQS attainment/1-hour NAAQS nonattainment areas. We 
have created a new section 51.905(a)(4) that addresses 8-hour NAAQS 
attainment/1-hour NAAQS maintenance areas. The section addressing that 
second category of areas is discussed below. An area that is 8-hour 
NAAQS attainment/1-hour NAAQS nonattainment will not be required to 
develop and submit outstanding attainment demonstration and ROP plans 
for the 1-hour NAAQS for so long as the area continues to maintain the 
8-hour NAAQS. However, if the area violates the 8-hour NAAQS prior to 
having an approved 8-hour maintenance plan under section 110(a)(1), the 
area will be required to submit a SIP revision to address outstanding 
ROP and attainment demonstration plans as follows.\41\
---------------------------------------------------------------------------

    \41\ We discuss the obligation for these areas to adopt a 
section 110(a)(1) maintenance plan below.
---------------------------------------------------------------------------

    (1) ROP Plans. For an outstanding 1-hour ROP plan, the State must 
submit a SIP providing for any outstanding ROP and the 3-year periods 
for achieving those reductions will begin January 1 of the year 
following the 3-year period on which EPA bases its determination. For 
example, if an area was required to and does not have an approved SIP 
providing for a 9% reduction in emissions from 1996-1999, the 
obligation to have such a SIP is deferred unless the area violates the 
8-hour NAAQS prior to having an approved maintenance plan for the 8-
hour NAAQS. If EPA determines in August 2007 that the area violated the 
8-hour NAAQS based on ambient air quality data from 2004-2006 and at 
that time the area does not have an approved maintenance plan for the 
8-hour NAAQS, the area will be required to submit a SIP providing for a 
9 percent reduction in emissions for the 3-year period of January 
2007--December 2009. The State may rely on national and regional 
controls for purposes of meeting this increment of reduction and the 9 
percent should be calculated using the 1990 baseline. (The 1-hour ROP 
requirement is calculated from a 1990 baseline, not a 2002 baseline, as 
is the 8-hour RFP requirement.) We have clarified the language in the 
final regulation to make clear that the requirement to submit the plan 
for additional emission reductions applies only to the extent that an 
area had not met its prior planning obligations. For example, if an 
area was classified as serious for the 1-hour NAAQS and had an approved 
15 percent ROP plan and an approved 9 percent ROP plan for 1996-1999, 
then the area does not have any outstanding ROP obligation that must be 
met under this provision. However, if the same area only had an 
approved 15 percent ROP plan, but not an approved 9 percent ROP plan 
for 1996-1999, then the area has an outstanding 9 percent ROP plan for 
the 1996-1999 period. If the State had submitted the ROP plan to EPA, 
but EPA had not yet acted on the submission, the State may notify EPA 
that it wishes to rely on the previously submitted SIP or it may elect 
to submit a new or revised SIP.
    We believe this approach makes sense as it ensures that the level 
of emission reduction that the area was required to achieve, but was 
not yet enforceable under the SIP, will be achieved expeditiously after 
a violation of the 8-hour NAAQS occurs.
    (2) Attainment Demonstration. For an outstanding 1-hour attainment 
demonstration, the final rule requires the State to either: (1) submit 
an 8-hour maintenance plan that addresses the violation and 
demonstrates maintenance through EPA-approved modeling; or (2) submit a 
plan to achieve a 3 percent increment of progress within 3 years after 
EPA determines the area has violated the NAAQS. The 3 percent increment 
of progress must be in addition to measures (or enforceable commitments 
to measures) in the SIP at the time of the effective date of 
designation and in addition to national or regional measures.
    This approach differs from both the June 2003 proposal and the 
draft regulatory text in that we do not establish precisely the same 
requirement for these areas that we establish for areas that are 8-hour 
NAAQS nonattainment/1-hour NAAQS nonattainment. For areas that are 8-
hour NAAQS nonattainment/1-hour NAAQS nonattainment, section 
51.905(a)(1)(ii) provides three options for the State. The first option 
available is that States may choose to submit their 1-hour SIP. We do 
not believe this option makes good policy sense for an area designated 
attainment for the 8-hour NAAQS to spend resources to develop a plan to 
achieve the 1-hour NAAQS (which is likely to have been revoked by that 
time), when the area will already be in the process of developing the 
section 110(a)(1) maintenance plan for the area discussed elsewhere in 
this preamble.
    The second and third options under section 51.905(a)(1)(ii) 
available to areas that are 8-hour NAAQS nonattainment/1-hour NAAQS 
nonattainment are analogous but not identical to the two options we 
provide for areas designated attainment for the 8-hour NAAQS. Both 
types of areas are provided with the option of achieving a specified 
increment of progress. For areas that are 8-hour NAAQS nonattainment/1-
hour NAAQS nonattainment, we established an increment of 5 percent and 
for those designated attainment for the 8-hour NAAQS, we established a 
3 percent increment. In general, we believe that those areas initially 
designated attainment for the 8-hour NAAQS will

[[Page 23981]]

have a less significant 8-hour problem--these areas tend to record 
values within a few parts per billion of the NAAQS. Thus, since the 
increment of progress is limited to controls not already adopted into 
the SIP or required by federal or regional controls, the 5 percent 
reduction requirement would likely be excessive for purposes of 
addressing that small deviation from the NAAQS.
    The third option available to areas that are 8-hour NAAQS 
nonattainment/1-hour NAAQS nonattainment is to submit an early 8-hour 
attainment demonstration. Since areas designated attainment for the 8-
hour NAAQS are not required to develop attainment demonstrations, it 
did not make sense to carry this option over. Rather, we determined it 
made more sense to allow the area to address the violation in the 
context of the obligation that it does have, i.e., to develop a 
maintenance plan for the 8-hour NAAQS. Thus, for these areas, we 
created the option of performing a more rigorous maintenance 
demonstration--a demonstration based on EPA-approved modeling.
    (C) Comments and responses.
    Comment: Some commenters on draft regulatory text objected to 
continuing the obligation for areas to submit ROP plans and/or 
attainment demonstrations for the 1-hour NAAQS after the 1-hour NAAQS 
is revoked. Some of the comments reflected the fact that the regulatory 
text may have been unclear regarding what the requirement entailed and 
which areas were affected.
    Response: We have designed the final rule such that an area with an 
unmet planning obligation would still be required to submit and 
implement a rate of progress plan and an attainment demonstration (or 
substitute plan) under the 1-hour NAAQS if the area violates the 8-hour 
NAAQS before it has an approved maintenance plan. These are areas that 
have historically had an ozone problem and, in general, have 8-hour 
design values within a few parts per billion of the 8-hour NAAQS. Once 
these areas have an approved 110(a)(1) maintenance plan with 
contingency measures, that plan will address future violations of the 
8-hour NAAQS and the 1-hour obligations will no longer apply. However, 
until that plan is in place, we believe that Congress would have 
intended these requirements to still have significance if the area 
violates the health-based NAAQS.
    The final regulatory text was modified to clarify that the 
provision applies to areas that do not have approved ROP plans and/or 
attainment demonstrations under the 1-hour NAAQS and that violate the 
8-hour NAAQS before having an approved 8-hour maintenance plan under 
section 110(a)(1). The regulatory text also clarifies the obligation 
that will apply.
    (v) Maintenance Plans for the 8-hour NAAQS. (Section VI.C.3.b(iii) 
of proposed rule; see 68 FR 32823; Section 51.905(a)(3)(iii)of draft 
and final rules).
    (A) Background.
    In the June 2003 proposal, we proposed that areas designated 
attainment for the 8-hour NAAQS and designated nonattainment for the 1-
hour NAAQS on or after November 15, 1990, must adopt and submit a 
maintenance plan consistent with section 110(a)(1) within 3 years of 
designation as attainment for the 8-hour NAAQS. The maintenance plan 
should provide for continued maintenance of the 8-hour NAAQS for 10 
years following designation for the 8-hour NAAQS and must include 
contingency measures. Areas with approved 1-hour maintenance plans 
under section 175A would be able to modify those maintenance plans 
consistent with their obligation to have a maintenance plan for the 8-
hour NAAQS under section 110(a)(1). Such areas could remove from their 
maintenance SIPs (a) the obligation to submit a maintenance plan for 
the 1-hour NAAQS 8 years after approval of their initial 1-hour 
maintenance plan; and (b) the requirement to implement contingency 
measures upon a violation of the 1-hour ozone NAAQS.
    The draft regulatory text reflected the description in the June 
2003 proposal.
    (B) Summary of final rule.
    We are adopting the approach we proposed. However, as noted above, 
we have now created separate subsections in the rule addressing areas 
that were designated nonattainment for the 1-hour NAAQS at the time of 
designation for the 1-hour NAAQS and areas that were maintenance areas 
for the 1-hour NAAQS at the time of designation for the 8-hour NAAQS. 
Section 51.905(a)(3)(iii) applies only to areas designated 
nonattainment for the 1-hour NAAQS at the time of designation for the 
8-hour NAAQS. Section 51.905(a)(4)(ii) establishes the same requirement 
for areas that are maintenance for the 1-hour NAAQS at the time of 
designation for the 8-hour NAAQS. These two provisions provide that 1-
hour NAAQS nonattainment/8-hour NAAQS attainment (section 
51.905(a)(3)(iii)) and 8-hour NAAQS attainment/1-hour NAAQS maintenance 
(section 51.905(a)(4)(ii)) areas must adopt and submit a maintenance 
plan consistent with section 110(a)(1) within 3 years of designation as 
attainment for the 8-hour NAAQS. The maintenance plan should provide 
for continued maintenance of the 8-hour NAAQS for 10 years following 
designation for the 8-hour NAAQS and should include contingency 
measures. We provide additional detail below regarding maintenance 
areas for the 1-hour NAAQS.
    Section 110(a)(1) requires all areas to demonstrate that they will 
attain and maintain the relevant NAAQS. Most of the areas addressed by 
this provision of the regulation have historically had problems meeting 
and/or remaining in attainment of the ozone NAAQS. We think it is 
important for States to ensure that these areas will continue to have 
clean air so that the health of citizens will be protected.
    (C) Comments and responses.
    Comment: A number of commenters who addressed this issue in 
comments on the June 2, 2003 proposal did not support the section 
110(a)(1) maintenance plan requirement. Some commenters believed the 1-
hour NAAQS should remain in effect and with it any existing 1-hour SIP 
requirements, including section 175A maintenance plan requirements 
(which would require conformity determinations). One commenter objected 
to the proposed requirement, alleging the requirement was unnecessary 
and not required. Two commenters agreed with the requirement.
    In commenting on the draft regulatory text one commenter supported 
this provision. One commenter recommended that we provide more specific 
guidance on preparation of section 110(a)(1) maintenance plans and also 
not require modeling for them. Two commenters objected to maintenance 
plans under section 110(a)(1) because they would not require conformity 
(as would maintenance plans under section 175A) for areas that 
currently have maintenance plans under the 1-hour NAAQS. The commenters 
believed the maintenance planning should be done under section 175A. 
Another commenter believed that section 110(a)(1) of the CAA requires 
neither contingency measures nor a 10-year plan; the commenter 
suggested that the section 110(a)(1) maintenance plan merely be a 
continuation of the provisions of the existing maintenance plan.
    Response: Because the 1-hour NAAQS would be revoked, the 
requirements of section 175A would not apply to these areas (areas 
initially designated attainment for the 8-hour NAAQS but that were 
designated nonattainment for the 1-hour NAAQS at the time of enactment 
of the 1990 CAA Amendments.) Section 175A applies to

[[Page 23982]]

redesignations, not to initial designations. After the 1-hour NAAQS is 
revoked, we believe that an area that was previously designated 
nonattainment for the 1-hour NAAQS or was designated attainment with a 
maintenance plan and that initially is designated attainment for the 8-
hour ozone NAAQS, should be required to demonstrate maintenance only 
for the 8-hour NAAQS at that point. The area was not ``redesignated'' 
attainment for the 8-hour NAAQS, and therefore the section 175A 
maintenance plan requirement does not apply. We believe that the 
section 110(a)(1) maintenance provisions--as required in section 
51.905--will provide adequate assurance of maintenance of the 8-hour 
NAAQS. The EPA always retains the authority to require a State that 
fails to maintain the NAAQS to revise its SIP to provide additional 
maintenance measures or to redesignate the area nonattainment and 
require an attainment demonstration.
    We do not agree with commenters that opposed a provision requiring 
a maintenance plan under section 110(a)(1) for these areas. We believe 
that the CAA requires that SIPs continue to provide for maintenance of 
the applicable NAAQS under section 110(a)(1). Because these areas have 
historically experienced ozone problems and generally are close to 
violating the 8-hour NAAQS, we believe it is prudent to require a 
demonstration of how they will maintain the 8-hour NAAQS. We think this 
requirement will benefit citizens by providing better assurance that 
the air will remain clean and will benefit industry by minimizing the 
likelihood the area will violate the standard and be redesignated to 
nonattainment.
    f. Section 51.905(a)(4): 8-Hour NAAQS Attainment/1-Hour NAAQS 
Maintenance.
    As noted above, in the preamble to the proposed rule, EPA addressed 
in the same section 1-hour nonattainment areas and 1-hour maintenance 
areas that are designated nonattainment for the 8-hour NAAQS. Comments 
on the proposed regulatory text noted that section 51.905(a)(3) only 
addressed 8-hour attainment areas that were designated nonattainment 
for the 1-hour ozone NAAQS and not areas that were maintenance for that 
NAAQS. Thus, the draft rule did not address all aspects of the proposal 
since it did not include provisions for areas that are maintenance for 
the 1-hour NAAQS at the time of designations.
    We considered revising paragraph 51.905(a)(3) to include 1-hour 
maintenance areas. However, that subsection included certain 
requirements not relevant for 1-hour maintenance areas, such as 
requirements concerning outstanding attainment demonstration and ROP 
plans. Thus, in the final rule, we created section 51.905(a)(4) to 
apply to areas designated attainment for the 8-hour NAAQS and that were 
maintenance areas for the 1-hour NAAQS at the time of designation for 
the 8-hour NAAQS.
    (i) Obligations in an approved SIP. (51.905(a)(4)(i)).
    This subsection is identical in structure to section 
51.905(a)(3)(i). Our reasons are explained in our discussion of section 
51.905(a)(3)(i), above.
    (ii) Maintenance plan. (51.905(a)(4)(ii). As provided above in the 
discussion of section 51.905(a)(3)(iii), we are adopting in our final 
rule our proposed interpretation regarding maintenance plans for areas 
designated nonattainment for the 1-hour NAAQS on or after November 15, 
1990 (i.e., areas that remain designated nonattainment for the 1-hour 
NAAQS as well as maintenance areas for the 1-hour NAAQS at the time of 
designation for the 8-hour NAAQS). Specifically, these areas must adopt 
a maintenance plan under section 110(a)(1) within 3 years of 
designation for the 8-hour NAAQS. The provision for maintenance areas 
is the same as for areas designated nonattainment for the 1-hour NAAQS. 
However, for maintenance areas, section 51.905(e), discussed below, 
cross-references this provision and addresses the relationship between 
the existing 1-hour maintenance plan and the 8-hour maintenance plan.
    Our reasons for adopting this provision are discussed above. 
Although these areas already have maintenance plans, those plans only 
address maintenance of the 1-hour NAAQS. It is important for these 
areas to ensure that they have a plan addressing maintenance of the 8-
hour NAAQS. These areas may evaluate their existing plan and 
demonstrate how it will ensure maintenance of the 8-hour NAAQS, or may 
modify their existing plan, or may adopt a new plan, as appropriate.
    Comment: One commenter argued that it makes little sense to require 
the State to continue to expend the effort and resources to update and 
extend these maintenance plans. The commenter questioned why a newly 
designated marginal area under the 8-hour NAAQS should be exempt from 
implementation plan requirements, while an area previously 
nonattainment for the 1-hour NAAQS, but now in attainment for both 
NAAQS, should be required to continue with 8 additional years of 
maintenance plan requirements.
    Response: The final rule (section 51.905(a)(4)) clarifies that 
these areas (areas that are initially designated attainment for the 8-
hour NAAQS but were attainment areas under the 1-hour NAAQS with 
approved maintenance plans) are relieved of the requirement to update 
their maintenance plan under section 175(A), but must submit a 
maintenance plan under section 110(a)(1) that provides for maintenance 
for 10 years. It should be noted that marginal areas under the 8-hour 
NAAQS are not ``exempt'' from implementation plan requirements; they 
are still subject to nonattainment new source review and conformity 
requirements, for instance. Furthermore, if a marginal area does not 
attain the NAAQS by its attainment date, the CAA requires that the area 
be bumped up in classification, which would require the area to submit 
a revised SIP with an attainment demonstration and control measures 
required under subpart 2 for the area's new classification. In 
addition, once the area attains the 8-hour NAAQS, it will be subject to 
the more stringent maintenance plan provision in section 175A, which 
requires the areas to demonstrate maintenance for 20 years.
3. For How Long Do These Obligations Continue To Apply? (Section VI.C.4 
of Proposed rule; See 68 FR 32824; Section 51.905(b) of Draft and Final 
Rules)
    a. Background. In the June 2, 2003 proposed rule, we proposed two 
options for when the State would no longer be required to continue 
implementing SIP-approved control obligations required for an area's 1-
hour classification. At that time, these requirements could be 
relegated to the contingency measures portion of the SIP if the State 
demonstrated that implementation of the controls was not necessary to 
attain or maintain the 8-hour NAAQS (consistent with section 110(l)). 
For simplification, we refer to this as the time control obligations 
may be shifted to the contingency measures. We clarified that the term 
``control obligations'' was intended to refer to the obligations which 
we determined would continue to apply under the preceding sections of 
the proposal, including the NOX transport rules. Under 
Option 1, control obligations could be shifted to contingency measures 
when the area achieves the level of the 1-hour ozone NAAQS (even if the 
area has not yet attained the 8-hour NAAQS). Under Option 2, control 
obligations could be shifted to contingency measures once the area 
attains and is redesignated to attainment for the 8-hour NAAQS 
(regardless of when, if ever, the area

[[Page 23983]]

attains the 1-hour NAAQS). The draft regulatory text was developed 
using Option 1 (when the area achieves the level of the 1-hour ozone 
NAAQS).
    b. Summary of final rule. We are adopting Option 2--control 
obligations an area is required to retain in the approved SIP for an 
area's 1-hour classification must continue to be implemented under the 
SIP until the area attains and is redesignated to attainment for the 8-
hour NAAQS. At that time, the State may relegate such controls to the 
contingency measure portion of the SIP if the State demonstrates in 
accordance with section 110(l) that doing so will not interfere with 
maintenance of the 8-hour NAAQS or any other applicable requirement of 
the CAA. If at the time the area is redesignated to attainment for the 
8-hour NAAQS the State has an outstanding obligation to adopt a control 
requirement under the 1-hour NAAQS, it remains obligated to do so, but 
may adopt it as a contingency measure. As discussed above, under EPA's 
Clean Data Policy, certain obligations such as the requirement to 
submit ROP plans and attainment demonstrations may be suspended based 
on a determination that the area has attained the 8-hour NAAQS and will 
no longer apply if the area is redesignated to attainment. However, if 
an area experiences a violation of the 8-hour NAAQS prior to being 
redesignated to attainment the requirements would once again apply.
    We are adopting this option because, as noted in the June 2, 2003 
proposal, the 8-hour NAAQS is the NAAQS that we have determined will 
protect public health and the environment. Only once an area 
demonstrates it has met and can maintain the health protective NAAQS do 
we believe it will be appropriate to shift these obligations to the 
contingency measures portion of the SIP. This scheme is consistent with 
what Congress intended. The CAA contemplates under subpart 2 that 
States must implement certain mandated requirements. Under the 
maintenance plan provision of the CAA (section 175A), such requirements 
may be shifted to the contingency measure portion of the SIP upon or 
after redesignation to attainment. Since the relevant NAAQS is now the 
8-hour NAAQS, we believe it is appropriate to require these mandated 
controls to remain as part of the implemented SIP until an area attains 
the 8-hour NAAQS and is redesignated to attainment. On or after that 
date, a State may move such obligation to the contingency measures 
portion of the SIP consistent with sections 175A and 110(l). Moreover, 
we believe it is appropriate to use attainment of the 8-hour NAAQS 
rather than attainment of the 1-hour NAAQS because, as provided 
elsewhere in this rulemaking, EPA will no longer be making 
determinations of whether an area has attained the 1-hour NAAQS and 
areas will not be required to demonstrate attainment or maintenance of 
the 1-hour NAAQS. Some areas may never attain the 1-hour NAAQS, as 
there will be no obligation to do so once it is revoked.
    The final rule covers the continued applicability of the 
NOX transport rules under section 51.905(f), rather than as 
an ``applicable requirement'' for purposes of section 110(l) because 
the NOX rules apply regardless of an area's attainment or 
nonattainment status for the 8-hour (or the 1-hour) NAAQS.
    c. Comments and responses
    Comment: Of the few commenters who addressed this issue in response 
to the June 2, 2003 proposal, several favored Option 1, and several 
favored Option 2. Of those who commented on the draft regulatory text, 
one commenter opposed the provision, and one comment was unclear as to 
the commenter's concerns. One other commenter supported the provision. 
Several commenters had clarifying questions.
    Response: Our rationale for the choice of Option 2 is presented 
above. A more detailed response to these and other comments appears in 
the RTC document.
4. Which Portions of an Area Designated for the 8-Hour NAAQS Remain 
Subject to the 1-Hour NAAQS Obligations? (Section VI.C.2 and 3 of 
Proposal; See 68 FR 32820-32821; 51.905(c) of the Draft and Final 
Rules)
    a. Background. In the June 2, 2003 notice, we proposed that the 
obligation to retain or to adopt and retain a mandatory control 
obligation applies only to the part of the 8-hour ozone nonattainment 
area that was designated nonattainment for the 1-hour ozone NAAQS. The 
proposal also provided an example of how this would work.
    The draft regulatory text provided additional specificity 
concerning geographic applicability of the anti-backsliding provisions. 
The draft text provided that with two exceptions only the portion of 
the designated area for the 8-hour NAAQS that was required to adopt the 
applicable requirements in 51.900(f) for purposes of the 1-hour NAAQS 
is subject to the obligations identified in paragraph (a) of this 
section with several exceptions. The first exception is an area that is 
designated nonattainment for the 8-hour NAAQS but that was 
nonattainment for the 1-hour NAAQS with an unmet obligation to submit 
an attainment demonstration; for these areas, the draft regulatory text 
provided that the entire area designated nonattainment for the 8-hour 
ozone NAAQS would be subject to the 10 percent advance increment of 
reduction. The second exception is an area that is attainment for the 
8-hour NAAQS but that was nonattainment under the 1-hour NAAQS with an 
unmet obligation to submit an attainment demonstration; for these 
areas, the 110(l) maintenance plan would have to demonstrate 
maintenance for the entire 8-hour ozone attainment area.
    b. Summary of final rule. The final rule incorporates most aspects 
of the approach as that contained in the proposal and in the draft 
regulatory text. The final rule provides that only the portion of the 
designated area for the 8-hour NAAQS that was designated nonattainment 
for the 1-hour NAAQS is required to comply with the obligations in 
subparagraph 51.905(a), except if the State elects to provide an early 
increment of progress or an early 8-hour attainment demonstration in 
lieu of an outstanding 1-hour attainment demonstration (for an 8-hour 
NAAQS nonattainment area/1-hour NAAQS nonattainment area under 
51.905(a)(1)(ii)(B) and (C)), the increment of progress or early 8-hour 
attainment plan must apply for purposes of the entire 8-hour 
nonattainment area.
    The final rule does not follow the approach in the proposal for the 
maintenance plan requirement for 8-hour attainment areas. The 
maintenance plans required under section 51.905(a)(3)(iii) and (4)(ii) 
must demonstrate maintenance only for the area designated nonattainment 
for the 1-hour NAAQS at the time of designation of the 8-hour NAAQS. We 
received comment that recommended this obligation apply only to the 
area that was originally designated nonattainment for the 1-hour NAAQS. 
After considering this comment and our discussion in the preamble to 
the proposed rule, we agree with the commenter. In many States, 
attainment areas are identified county by county rather than 
identifying a group of counties as an attainment area. Thus, a State 
may have one or more groups of counties listed as a nonattainment area 
and then the remaining counties in the State are each identified 
individually as ``attainment.'' See e.g., 40 CFR 81.311 (Georgia); 
81.329 (Nevada). Because the area that historically had a problem 
attaining the ozone NAAQS is the area

[[Page 23984]]

that was previously designated nonattainment for the 1-hour NAAQS, we 
believe it makes the most sense to require the maintenance plan for the 
area previously designated nonattainment for the 1-hour NAAQS. We will 
set forth in 40 CFR Part 81, Subpart E, an identification of the 
boundaries of areas and the area designations and classifications for 
the 1-hour NAAQS at the time of the 8-hour designations.
    c. Comments and responses.
    Comments on June 2, 2003 Proposal: With regard to limiting the 
applicability of 1-hour obligations to that portion of the 8-hour 
nonattainment area that was also part of the 1-hour nonattainment area, 
one commenter supports this policy, especially for the enhanced I/M 
program. The commenter believes that the environmental benefit of 
requiring an extension of the enhanced I/M program to areas recently 
added to the CMSA and designated nonattainment for the 8-hour NAAQS to 
be minimal, costly, and disruptive of the continued implementation of 
the enhanced I/M program in the current 1-hour nonattainment area.
    One commenter objected to requiring the substitute planning 
requirement (10 percent advance increment of emission reductions) that 
applies to areas with an outstanding attainment demonstration for the 
entire 8-hour ozone nonattainment area. Instead, the commenter 
recommended it should only apply to the 1-hour nonattainment area.
    Response: The final rule provides for retaining applicable emission 
control requirements for an area's 1-hour classification in only the 
original 1-hour nonattainment area.
    As noted in the final rulemaking notice, we are now allowing the 
State to meet its unmet 1-hour attainment demonstration obligation by 
submitting the outstanding attainment demonstration or by taking one of 
two early actions for 8-hour planning: achieve a 5 percent advance 
increment of emission reductions or submit an early 8-hour attainment 
demonstration. The advance increment of emission reductions is applied 
throughout the entire 8-hour nonattainment area because, although it is 
being submitted in lieu of the 1-hour requirement, it is intended to 
address the 8-hour nonattainment problem. Similarly, the 8-hour 
attainment demonstration is intended to address attainment for the full 
8-hour area. Because these alternatives to the 1-hour attainment 
demonstration are intended to address attainment and progress toward 
the 8-hour NAAQS, the State would need to apply these requirements, if 
selected, to the entire 8-hour nonattainment area. We developed these 
alternatives in response to concerns that areas focus on the 8-hour 
NAAQS rather than on the 1-hour NAAQS and that continued planning 
obligations for the 1-hour NAAQS would burden State resources. States 
still have the flexibility to choose to develop the 1-hour attainment 
demonstrations for the 1-hour area if they would like to restrict the 
unmet planning obligation to the old area.
5. What Obligations That Applied for the 1-Hour NAAQS Will No Longer 
Apply After Revocation of the 1-Hour NAAQS for an Area? (Section 
VI.C.3.d. of Proposal; See 68 FR 32824; Section 51.905(e) of Proposed 
and Final Rules)
    a. Background. In the June 2, 2003 proposed rule (68 FR 328224), we 
proposed that once the 1-hour NAAQS is revoked, EPA would no longer 
make findings of failure to attain that NAAQS and, therefore, we would 
not reclassify areas based upon a finding that the area failed to 
attain the 1-hour NAAQS. We indicated areas should focus their 
resources on attainment of the 8-hour NAAQS and stated that we believed 
it would be counterproductive to establish new obligations for States 
with respect to the 1-hour NAAQS after they have begun planning for the 
8-hour NAAQS. In addition, we noted that the attainment dates for areas 
classified as marginal, moderate and serious had passed and that the 
CAA does not provide for reclassification of severe areas. We also 
noted other mechanisms that are available to make sure that States 
continue to make progress toward attaining the 8-hour NAAQS.
    In addition, we indicated that conformity requirements would no 
longer apply for the 1-hour NAAQS once the NAAQS is revoked. The June 
2, 2003 proposal explains that, under section 176(c) of the CAA, 
conformity applies to areas designated nonattainment or subject to the 
requirement to develop a maintenance plan pursuant to section 175A. 
Once the 1-hour NAAQS is revoked, areas would no longer be designated 
nonattainment for the 1-hour NAAQS or subject to the obligation to 
develop a maintenance plan under section 175A for the 1-hour NAAQS and 
thus would no longer be subject to the obligation to demonstrate 
conformity (either transportation conformity or general conformity) for 
that NAAQS.
    The draft regulatory text incorporated these concepts and also 
provided that, at the time of revocation of the 1-hour NAAQS, any 
provisions of applicable SIPs that require conformity determinations in 
such areas for the 1-hour NAAQS will no longer be enforceable as a 
matter of law pursuant to section 176(c)(5) of the CAA.
    Additionally, the draft regulatory text reflected the discussion in 
the preamble to the proposed rule regarding what portions of a 1-hour 
maintenance plan could be revised or removed once the 1-hour NAAQS was 
revoked (68 FR 32823). The draft regulatory text provided that areas 
with approved 1-hour maintenance plans could modify those plans to 
remove the obligation to submit a maintenance plan for the 1-hour NAAQS 
eight years after approval of the initial 1-hour maintenance plan and 
to remove the obligation to implement contingency measures upon a 
violation of the 1-hour NAAQS. The draft regulatory text provided, 
however, that these requirements would remain enforceable until EPA 
approved a SIP removing or revising them and also provided that EPA 
would not approve such revisions until EPA approves an 8-hour 
attainment demonstration for an area designated nonattainment for the 
8-hour NAAQS or an 8-hour maintenance plan for an area designated 
attainment for the 8-hour NAAQS. Finally, EPA noted that such a SIP 
revision must also be consistent with sections 110(l) and 193 of the 
CAA.
    b. Summary of final rule.
    We are adopting the approach we set forth in our proposed rule and 
providing clarification regarding the penalty obligations under 
sections 181(b)(4) and 185 of the CAA that apply in severe areas that 
do not attain the 1-hour NAAQS by the applicable attainment date. The 
final rule provides that as of the effective date of revocation of the 
1-hour NAAQS:
     We will no longer make findings of failure to 
attain the 1-hour NAAQS and, therefore, (a) we will not reclassify 
areas to a higher classification for the 1-hour NAAQS based on such a 
finding, and (b) areas that were classified as severe for the 1-hour 
NAAQS are not obligated to impose fees as provided under sections 
181(b)(4) and 185 of the CAA.
     Areas will not be obligated to continue to 
demonstrate conformity for the 1-hour NAAQS as of the effective date of 
the revocation of the 1-hour NAAQS.
     An area with an approved 1-hour maintenance plan 
under section 175A of the CAA may modify its maintenance plan to: (1) 
Remove the planning obligation to develop the second 10-year 
maintenance plan for the 1-hour NAAQS; and, (2) replace the existing 1-
hour contingency measure trigger with an 8-hour value. However, before 
the EPA can consider approving such a

[[Page 23985]]

revision, certain conditions must be met. If the area is designated 
nonattainment for the 8-hour ozone NAAQS, it must first have an 
approved 8-hour attainment demonstration in place. If the area has been 
designated as attainment for the 8-hour ozone NAAQS, it must first have 
an approved section 110(a)(1) maintenance plan in place for the 8-hour 
NAAQS.
     NSR under the 1-hour NAAQS will no longer apply 
in areas that are 8-Hour NAAQS nonattainment/1-Hour NAAQS 
nonattainment.
    Each of these provisions is discussed further below.
    (i) Findings of Failure to Attain the 1-hour NAAQS. We continue to 
believe, as stated in the preamble to the proposed rule, that areas 
should focus their resources on attainment of the 8-hour NAAQS and that 
it would be counterproductive to establish new obligations for States 
with respect to the 1-hour NAAQS after they have begun planning for the 
8-hour NAAQS. Moreover, we do not believe there is a basis to determine 
whether an area has met the 1-hour NAAQS once that NAAQS no longer 
applies; once the 1-hour NAAQS is revoked, there will not be an 
applicable attainment date with which to make a determination as to 
whether an area has met its attainment date or not. Since the 
obligations to reclassify areas and impose fees are based on a 
determination that an area has failed to meet the NAAQS by the 
appropriate attainment date, those obligations also would no longer 
apply for the 1-hour NAAQS once the 1-hour NAAQS has been revoked.
    While we did not specifically state in our proposal that severe 
areas would no longer be obligated to impose fees under sections 
181(b)(4) and 185 based on a failure to attain the 1-hour NAAQS after 
the effective date of the revocation of the 1-hour NAAQS, it is a 
logical extension of our proposal as that obligation is triggered by a 
finding of failure to attain. In addition, this is consistent with 
Appendix B of the June 2, 2003 proposal, which did not identify the 
section 185 fee provision as an applicable requirement.
    (ii) Conformity under the 1-hour NAAQS. Regarding conformity, we 
are adopting the approach we set forth in our proposed rule (68 FR 
32823). The final rule provides that, upon revocation of the 1-hour 
NAAQS for an area, conformity determinations will no longer be required 
for the 1-hour NAAQS. At that time, any provisions of applicable SIPs 
that require conformity determinations for the 1-hour NAAQS in such 
areas will no longer be enforceable pursuant to section 176(c)(5) of 
the CAA.
    Under section 176(c) of the CAA, conformity applies to areas 
designated nonattainment or subject to the requirement to develop a 
maintenance plan pursuant to section 175A for a specific NAAQS. Once 
the 1-hour NAAQS is revoked, areas designated attainment for the 8-hour 
NAAQS would no longer be subject to the obligation to demonstrate 
conformity for the 1-hour NAAQS and would have no conformity obligation 
for the 8-hour NAAQS. Likewise, even areas designated nonattainment for 
the 8-hour NAAQS would no longer have an obligation to demonstrate 
conformity under the 1-hour NAAQS. The reason for this is that these 
areas would no longer be designated nonattainment for the 1-hour NAAQS 
and would no longer be required to develop a maintenance plan under 
section 175A for purposes of the 1-hour NAAQS.
    (iii) 1-hour maintenance plans. Regarding the revisions to 1-hour 
maintenance plans, as noted above, upon revocation of the 1-hour NAAQS, 
an area with an approved 1-hour maintenance plan under section 175A of 
the CAA may modify the maintenance plan to remove both the obligation 
to submit a second maintenance plan for the 1-hour NAAQS 8 years after 
approval of the initial 1-hour maintenance plan and the obligation to 
implement contingency measures upon a violation of the 1-hour NAAQS. 
The maintenance plan requirements will remain enforceable as part of 
the approved SIP until such time as EPA approves a SIP revision 
removing such obligations. We will not approve a SIP revision 
requesting these modifications until the State submits and EPA approves 
an attainment demonstration for the 8-hour NAAQS for an area designated 
nonattainment for the 8-hour ozone NAAQS or a maintenance SIP for the 
8-hour NAAQS for an area designated attainment for the 8-hour NAAQS. 
Any revision to such SIP must meet the requirements of section 110(l) 
and 193 of the CAA.
    (iv) New Source Review under the 1-hour NAAQS. As noted above 
concerning anti-backsliding provisions related to growth measures, our 
June 2, 2003 proposal indicated that 1-hour NSR requirements would 
continue to apply in a nonattainment area if that area's classification 
under the 1-hour ozone standard (at the time of designation for the 8-
hour standard) is higher than its classification under the 8-hour 
standard (68 FR 32821). We indicated at proposal that Congress intended 
each area that was classified for the 1-hour ozone NAAQS under subpart 
2 to adopt the specified control obligations in subpart 2 for the 
area's 1-hour classification. Accordingly, we proposed that the 1-hour 
NSR obligations continue to apply after revocation.
    We have now determined that it is inappropriate to mandate that a 
State continue to apply 1-hour nonattainment NSR requirements to such 
areas. Therefore, today's final rule specifies that, at the time that 
the 1-hour NAAQS is revoked, a state is no longer required to retain a 
nonattainment NSR program in its SIP based on the requirements that 
applied by virtue of the area's previous classification under the 1-
hour standard. Instead, State implementation plans will be required to 
include an NSR program based on the area's designation and 
classification under the 8-hour standard.
    Accordingly, a State may request approval of a SIP revision to 
remove its 1-hour nonattainment NSR program from its SIP. We will 
approve such changes to a State's SIP because we have determined based 
on section 110(l) of the Act that such changes will not interfere with 
any State's ability to reach attainment of the 8-hour standard and will 
be consistent with reasonable further progress.
    For example, upon approval of a SIP revision for a nonattainment 
area that we classify as marginal for the 8-hour standard, the major 
source threshold would be 100 tpy and the offset ratio would be at 
least 1.1:1. Any lower major stationary source threshold and higher 
offset ratio that applied by virtue of the area's previous 1-hour 
classification would no longer apply. For areas that must comply with 
nonattainment NSR requirements solely based on the area's location 
within the Ozone Transport Region under Section 184 of the Act, there 
will be no change in the major stationary source threshold or offset 
ratio as these requirements remain the same for the 8-hour standard.
    Although the proposal identified nonattainment NSR as a measure to 
address growth and not a control obligation, we proposed to treat NSR 
in the same manner as control obligations. We stated that such 
requirements should continue to apply based on Congressional intent to 
prohibit States from altering or removing provisions from SIPs if the 
SIP revision would jeopardize the air quality protection provided in 
the approved plan. 68 FR at 32819. We further concluded that Congress 
intended the specified control obligations in subpart 2 to continue to 
apply after revocation by virtue of the 1-hour classifications.

[[Page 23986]]

    Upon further reflection, and consideration of public comments, we 
have revised our approach concerning NSR in areas that were non-
attainment for the 1-hour NAAQS and continue to be nonattainment under 
the 8-hour NAAQS. While some commenters believed that NSR requirements 
that are part of SIPs submitted to meet 1-hour NAAQS requirements 
should be retained, several preferred that the 1-hour NSR program be 
replaced by an NSR program under the 8-hour standard when the 1-hour 
standard is revoked. Other commenters supported removing the 1-hour NSR 
requirements based on a showing that removing the requirements would 
not interfere with attainment or maintenance of the 8-hour standard. We 
agree with these commenters that there is no need to retain 1-hour NSR 
programs upon a finding under section 110(l) that 8-hour NSR will not 
interfere with the State's ability to reach attainment of the 8-hour 
standard. Moreover, we note major NSR only applies to new sources and 
to existing sources that have a physical change or change in the method 
of operation. Therefore, emission limitations and other requirements in 
NSR permits issued under 1-hour NSR programs will continue to be in 
force when the 1-hour NAAQS is revoked.
    Also, our revised approach is more consistent with our longstanding 
treatment of NSR as a growth measure. We have historically treated 
control measures differently from measures to control growth. We 
provided no rationale in our proposal for treating control measures and 
growth measures in the same manner for purposes of the 8-hour standard, 
in contrast with our historical approach.
    Unlike control requirements such as RACT and I/M, the NSR program 
is a growth measure and is not specifically designed to produce 
emissions reductions. Instead, its purpose is to allow new source 
growth to occur without interfering with an area's ability to attain. 
The statute and regulatory history identify nonattainment NSR as a 
growth measure. Thus, we have previously concluded that NSR is not a 
``control'' measure in the context of Section 175A maintenance plans. 
See 68 FR 25418, 25436 (May 12, 2003). Specifically, we explained that 
the requirement that contingency provisions include ``control'' 
measures does not include nonattainment NSR. We reasoned that the LAER 
and offset requirements included in existing NSR permits would remain 
in effect for those sources. Thus, the LAER and offset measures that 
were relied upon to attain the NAAQS would remain in effect after the 
nonattainment NSR program was replaced. We also noted that another 
preconstruction review program (in that context, PSD) would be 
triggered to limit growth consistent with attainment in the future. 
Those considerations apply with equal force here, as discussed in more 
detail below.
    The role of the NSR permitting program as a growth measure, rather 
than a control measure, is evident in the structure of the Act, which 
delineates nonattainment NSR and control measures as separate SIP 
requirements. In the general requirements for nonattainment plan 
provisions, NSR permits are listed in CAA 172(c)(5), while control 
measures are listed in CAA 172(c)(6). Similarly, in defining 
implementation plan requirements, CAA 110(a)(2)(C) sets forth the 
requirement for permit programs and CAA 110(a)(2)(A) the control 
measures. As we explained in our 1994 policy memo,\42\ if the term 
``measures,'' as used in sections 110(a)(2)(A) and 110(a)(2)(C), had 
been intended to include PSD and part D NSR, there would have been no 
point to requiring that SIPs include both measures and preconstruction 
review. Section 172(e), which applies when EPA relaxes a NAAQS, only 
requires EPA to ensure that ``controls'' are no less stringent than 
they were for the more stringent NAAQS that has been replaced. It 
contains no specific requirements concerning growth measures.
---------------------------------------------------------------------------

    \42\ Part D New Source Review (part D NSR) Requirements for 
Areas Requesting Redesignation to Attainment, October 14, 1994, from 
Mary D. Nichols.
---------------------------------------------------------------------------

    Moreover, the statute is clear regarding the roles of the NSR 
program and control measures in nonattainment areas. CAA 172(a)(2) 
requires attainment as expeditiously as practicable considering control 
measures and CAA 172(c)(1) and (c)(6) require implementation of all 
control measures as expeditiously as practical to provide for 
attainment of the NAAQS by the area's attainment date. Conversely, CAA 
173(a)(1)(A) requires only that growth due to proposed sources, when 
considered together with the other plan provisions required under 
section 172, be sufficient to ensure RFP. Thus, unlike the control 
measures required by section 172(c)(1) and (c)(6), NSR is not a measure 
in and of itself to assure attainment of the NAAQS. Rather, NSR should 
be considered in conjunction with a State's control measures to assure, 
consistent with the requirements in Section 172(c)(4), that the 
emissions from new sources will be consistent with RFP and not 
interfere with attainment of the applicable NAAQS.
    In light of these different statutory goals, we believe the 
appropriate review of NSR SIP revisions under the 8-hour standard is 
whether: (1) The SIP revision is consistent with reasonable further 
progress; and whether (2) the SIP revision will not interfere with the 
ability to attain.
    With regard to the specific requirements of 110(l), we do not 
believe that States need to make any case-specific demonstration that 
replacing the 1-hour NSR program with an NSR program based on the 
area's 8-hour classification satisfies the Section 110(l) requirements. 
As one commenter noted, NSR is a prospective permitting program that 
only applies to future emissions from new and modified sources. Any 
source that is subject to the 1-hour NSR requirements is required to 
continue to comply with those requirements. In this respect, there will 
be no degradation of air quality by virtue of this SIP change. 
Moreover, unlike control measures, States do not rely on the NSR 
program to generate emissions reductions to move an area further toward 
attainment. The essential question is whether the NSR program changes 
will hinder future air quality improvements based on future growth 
projections. Such a question inherently involves a look at the present 
day air quality, which is best reflected by the current 8-hour 
classifications. As long as the State plans to manage growth within the 
emissions inventory and include growth in their attainment plans, new 
source growth will be consistent with RFP and not interfere with the 
State's ability to attain. Therefore, we believe that the 8-hour NSR 
program requirements, based on an area's present air quality needs, 
will assure that progress continues toward attainment despite future 
economic growth.
    c. Comments and responses.
    (i) Comments on June 2, 2003 proposal:
    Comment: Several commenters addressed this issue. Most agreed with 
the proposal, but recommended that we clarify that the section 185 
penalty fees would not be imposed after the 1-hour NAAQS is revoked. A 
few of the commenters disagreed on the basis that EPA should not revoke 
the 1-hour NAAQS and that all requirements that apply for purposes of 
the 1-hour NAAQS remain applicable.
    Regarding conformity, the majority of commenters that addressed 
this issue objected to EPA's proposal. Most of these commenters 
believed the 1-hour NAAQS and any 1-hour SIP budgets

[[Page 23987]]

should remain in effect, such that for an area that was designated 
nonattainment under the 1-hour NAAQS, or was redesignated to attainment 
and had an approved maintenance plan under the 1-hour NAAQS, conformity 
requirements would still apply. Given the variety of comments we 
received about how conformity will be implemented, in this section we 
provide a response following each type of comment.
    Several commenters indicated that revoking the 1-hour NAAQS for 
conformity is backsliding, and offered several arguments for why the 1-
hour budgets should be retained in 1-hour nonattainment and maintenance 
areas.
    Some commenters indicated that once approved, the motor vehicle 
emissions budget is part of the applicable implementation plan, and EPA 
may not render them nugatory for conformity purposes. Commenters also 
asserted that EPA may not unilaterally revise a state's SIP or suspend 
it, and in order to require states to revoke the budgets in their SIPs, 
EPA would have to find the budgets inadequate. Further, commenters 
argued that EPA may not lawfully allow states to discontinue 
implementation of the budgets in their current SIPs, and if states were 
to decide on their own that budgets no longer apply for conformity 
purposes, commenters said that EPA would be obligated to impose 
sanctions pursuant to section 179(a)(3). Commenters asserted that 
states may not revise their SIPs to remove budgets without complying 
with section 110(l), which states that EPA cannot approve revisions 
``if the revision would interfere with any applicable requirement 
concerning attainment and reasonable further progress (as defined in 
section 171), or any other applicable requirement of this Act.''
    Response: The CAA specifically states that conformity applies only 
in ``a nonattainment area* * *'' and ``an area that was designated as a 
nonattainment area but that was later redesignated by the Administrator 
as an attainment area and that is required to develop a maintenance 
plan under section 7505a of this title* * *'' (42 U.S.C. 7506(5)). 
Therefore, CAA section 176(c)(5) restricts conformity to nonattainment 
areas and areas that are required to submit maintenance plans under 
section 175A; in these areas, the Federal government's sovereign 
immunity is waived so that states can require conformity to be 
determined by the U.S. Department of Transportation. However, after 
revocation of the 1-hour NAAQS, the areas previously nonattainment for 
the 1-hour NAAQS are no longer nonattainment for that NAAQS. Similarly, 
after revocation of the 1-hour NAAQS, the areas previously required to 
submit section 175A maintenance plans under the statute for the 1-hour 
NAAQS will no longer be required to do so. Therefore, after revocation 
the statute will no longer waive sovereign immunity to allow States to 
require the U.S. Department of Transportation to perform conformity 
determinations.
    States are not taking any action to remove the budgets for the 1-
hour ozone NAAQS in their SIPs, nor are they required to do so. In 
fact, EPA has proposed that 8-hour nonattainment areas would be able to 
use the 1-hour budgets for conformity for the 8-hour NAAQS, if they 
exist in an area (November 5, 2003, proposed rule, 68 FR 62690). Thus, 
although the 1-hour budgets would remain in the SIP, areas previously 
designated nonattainment or maintenance for the 1-hour NAAQS would no 
longer be required or even authorized to show conformity under CAA 
section 176(c)(5) for that NAAQS. Similarly, EPA would have no grounds 
for imposing sanctions where conformity is not conducted in these areas 
because there would be no SIP planning or implementation failure, since 
any SIP provisions requiring conformity would become unenforceable 
under section 176(c)(5) after revocation. EPA also disagrees that 
States cannot revise their SIPs to remove budgets without a 
demonstration that 110(l) is met, because states will not be revising 
their SIPs to remove budgets.
    As we acknowledged in our June 2, 2003, proposal, EPA's conclusion 
that conformity cannot apply in 1-hour maintenance areas once the 1-
hour NAAQS is revoked differs from the approach we planned to take in 
1997. In 1997, we interpreted revoking the 1-hour ozone NAAQS to mean 
that conformity would not apply for the 1-hour ozone NAAQS in areas 
that were nonattainment for the 1-hour ozone NAAQS, but that conformity 
would continue to apply for the 1-hour ozone NAAQS in areas with a 
maintenance plan. However, the 1997 interpretation would lead to an 
unfair and counter-intuitive result: areas that had attained the NAAQS 
and had made the effort to establish a maintenance plan would have to 
continue a required program, but areas that had not attained would not. 
We reconsidered this result and found it to be unfair and 
inappropriate. Further, upon reanalyzing CAA section 176(c)(5), we 
concluded that this interpretation did not fit with the text of the 
statute.
    Although section 110(l) would normally require areas to demonstrate 
that removing prior SIP requirements would not interfere with any 
applicable requirements of the CAA, where the CAA itself now forbids 
application of a prior requirement such a demonstration would be 
unnecessary. Further, it would interfere with the statutory limitation 
on the applicability of conformity to require conformity determinations 
in areas that are no longer required by the CAA to submit section 175A 
maintenance plans.
    Comment: Commenters remarked that revoking the 1-hour ozone NAAQS 
is of particular concern in areas that are currently nonattainment or 
maintenance for the 1-hour ozone NAAQS that will be designated 
attainment for the 8-hour ozone NAAQS, because once the NAAQS is 
revoked, these areas will no longer be subject to conformity. A couple 
of commenters made the point that revoking the 1-hour NAAQS would have 
economic implications for their area because without transportation 
conformity, the emissions from the transportation sector could grow 
without restraint and therefore, emissions from the industrial sector 
would have to be limited further. Commenters were also concerned that 
their region would lose the ability to forecast whether a violation 
could occur.
    Response: We promulgated the 8-hour ozone NAAQS in response to the 
latest data and science regarding ozone; we believe the 8-hour ozone 
NAAQS is more protective of public health. In 1997, EPA made the 
decision to replace the 1-hour ozone NAAQS with the 8-hour ozone NAAQS, 
because EPA concluded that the 1-hour NAAQS is not needed to protect 
health and welfare.
    It is our conclusion that areas that are in attainment for the 8-
hour NAAQS would not be subject to conformity because the statute 
explicitly limits the applicability of conformity to designated 
nonattainment and maintenance areas. These areas still have an 
incentive to monitor the growth of emissions from the transportation 
sector; if these areas violate the 8-hour NAAQS, EPA could redesignate 
them as nonattainment for the 8-hour NAAQS and conformity would then 
apply.
    The EPA notes that although States could not implement conformity 
for attainment areas as a matter of federal law, they could still work 
with their MPOs to estimate regional emissions that would be generated 
by the planned transportation system to see whether a violation could 
occur and to address motor vehicle emissions growth. These type of 
State activities may be done

[[Page 23988]]

under State law, when possible, or on a voluntary basis.
    Comment: One commenter supports, in part, our proposal to allow 
amendment of maintenance plans, but takes issue with the fact that 
States would face a continuing obligation to implement contingency 
measures after revocation of the 1-hour NAAQS and the criteria for 
approval of such amendments. After the 1-hour NAAQS is revoked, a 
State's obligation to implement contingency measures should 
automatically be lifted. The Illinois EPA recommends that amendments to 
the maintenance plans for these areas be approved after the 1-hour 
NAAQS has been revoked.
    Response: Once we revoke the 1-hour NAAQS, the requirement for 
submission or subsequent revision of a section 175A maintenance plan 
under the 1-hour NAAQS no longer apply. The State still has an 
obligation to ensure that air quality remains clean and to invoke 
contingency measures in accordance with the terms of the approved SIP. 
The final rule provides that, upon revocation of the 1-hour NAAQS, an 
area with an approved 1-hour maintenance plan under section 175A of the 
CAA may modify the maintenance plan to remove the obligation to submit 
a maintenance plan for the 1-hour NAAQS 8 years after approval of the 
initial 1-hour maintenance plan and to remove the obligation to 
implement contingency measures upon a violation of the 1-hour NAAQS. 
The final rule provides that EPA would not approve a SIP revision 
requesting these modifications until the State submits and EPA approves 
an attainment demonstration for the 8-hour NAAQS for an area initially 
designated nonattainment for the 8-hour ozone NAAQS or a maintenance 
SIP for the 8-hour NAAQS for an area initially designated attainment 
for the 8-hour NAAQS. Any revision to such SIP must meet the 
requirements of section 110(l) and 193 of the CAA. For areas that are 
not required to submit attainment demonstrations (e.g., marginal 
areas), the SIP revisions that affect prior maintenance plans under the 
1-hour NAAQS may be made when other portions of the 8-hour SIP are due 
(e.g, the NSR provisions). The EPA disagrees with the comments that 
certain obligations in the maintenance plan should no longer apply upon 
revocation of the 1-hour NAAQS. The EPA believes that in order to 
ensure that these revisions will not interfere with attainment or 
maintenance of the 8-hour NAAQS, these areas should first have an 
approved 8-hour attainment or maintenance SIP in place.
    Comment: A commenter recommended that, in general, the rule should 
make it clear that any SIP revisions must comply with Sections 110(l) 
and 193.
    Response: The proposed rule--as well as the final rule--provides 
that EPA will not approve revisions to the maintenance plan until EPA 
approves the area's 8-hour SIP for either attainment or maintenance, 
which will ensure non-interference with the 8-hour NAAQS. However, the 
final rule also includes a requirement that the changes must be in 
accordance with sections 110(l) and 193. Several commenters supported 
the proposed rule. Other commenters believed the 1-hour NAAQS should 
not be revoked at all, and therefore there would not be a need for the 
anti-backsliding provision regarding NSR.
    Response: We address the issue of the revocation of the 1-hour 
NAAQS elsewhere in this notice and do not repeat it here.
    (ii) Comments on draft regulatory text (sect. 51.905(e) of the 
draft):
    Comment: One commenter believes that proposed 40 CFR 51.905(e)(1) 
contains an apparent misstatement that EPA should correct. That 
provision states that upon revocation of the 1-hour NAAQS, an area with 
an approved maintenance plan for that NAAQS may modify that plan to 
remove the obligation under CAA Sec.  175A(b) to submit a ``second 
round'' maintenance plan eight years after redesignation to attainment 
and to remove the obligation to implement contingency measures upon a 
1-hour NAAQS violation. The provision goes on to say that EPA will not 
approve a SIP revision making these modifications until the state 
submits and EPA approves: (1) An 8-hour attainment demonstration, if 
the area is designated nonattainment for the 8-hour NAAQS; or (2) an 8-
hour maintenance SIP under proposed 40 CFR 51.905(a)(3)(iii), if the 
area is designated attainment for the 8-hour NAAQS. Option (2) does not 
make sense, however. Proposed 40 CFR 51.905(e) by its terms applies to 
areas with approved 1-hour maintenance plans. Thus, these areas by 
definition have been redesignated to attainment--i.e., are no longer 
nonattainment--for the 1-hour NAAQS. Yet proposed 40 CFR 
51.905(a)(3)(iii) applies only to areas that are ``designated 
nonattainment for the 1-hour NAAQS at the time of revocation of the 1-
hour NAAQS.'' Thus, contrary to the last clause of Sec.  51.905(e)(l), 
areas that are maintenance for the 1-hour NAAQS and attainment for the 
8-hour NAAQS cannot be subject to Sec.  51.905(a)(3)(iii).
    Response: The commenter has pointed out a flaw in the proposal. The 
final rule has been modified from the proposal to account for this 
situation. A separate parallel provision has been established in 
section 51.905(a)(4) requiring 1-hour maintenance plan areas to submit 
a maintenance plan under section 110(a)(1). As provided earlier, EPA 
has also changed the proposed regulatory text--consistent with the June 
proposal--to indicate that 51.905(a)(3) and (4) apply, respectively to 
areas that are nonattainment or maintenance of the 1-hour NAAQS at the 
time of designation for the 8-hour NAAQS. Section 51.905(e)(1) has been 
modified to provide that the State would not be able to modify an 
existing 1-hour maintenance plan until EPA approves the new 8-hour 
maintenance plan.
    Comment: One commenter provided suggested language changes to 
section 51.905(e) that would retain the section 175A maintenance plan 
and the conformity requirement.
    Response: As noted above, once EPA revokes the 1-hour NAAQS, and 
the area is an 8-hour attainment area, section 175A maintenance 
provisions do not apply and conformity for the 1-hour NAAQS no longer 
applies.
6. What Is the Continued Applicability of the NOX SIP Call 
After Revocation of the 1-Hour NAAQS? (Section VI.C.3.c. of Proposal; 
See 68 FR 32824; Section 51.905(f) of the Proposed and Final Rules)
    a. Background. In the June 2, 2003 proposal (68 FR 32824), we noted 
that it is important to ensure that the transition to the 8-hour NAAQS 
does not jeopardize the controls required to be in place under the 
NOX SIP Call rule and the section 126 rule (i.e., the rules 
for addressing the long-range transport of ozone and its precursor, 
NOX). We jointly referred to these rules in the proposal as 
the NOX transport rules. We indicated that we plan to lift 
the stay of the 8-hour basis for the NOX transport 
rules.\43\ Regardless of whether we lift

[[Page 23989]]

that stay, the controls required have substantial benefits for 
reductions of both 1-hour and 8-hour ozone levels. We indicated that we 
believe that relaxing such controls would be contrary to the principles 
we identified in the proposal for an effective transition. Thus, we 
proposed that States must continue to adhere to the emission budgets 
established by the NOX transport rules after the 1-hour NAAQS is 
revoked in whole or in part.
---------------------------------------------------------------------------

    \43\ When EPA promulgated the NOX SIP Call, we 
required the same level of reductions for both the 1-hour and 8-hour 
ozone NAAQS (63 FR 57356, October 27, 1998). In response to the 
Court of Appeals remand of the 8-hour NAAQS, EPA stayed the 8-hour 
basis of the NOX SIP Call (65 FR 2674, January 18, 2000). 
However, since the same level of reductions was required for both 
the 8-hour and 1-hour NAAQS, the stay had no practical effect on 
States' compliance with the rule. Because EPA also stayed the 8-hour 
portion of the Section 126 Rule, we did not move forward to make the 
section 126 findings under the 8-hour NAAQS which would trigger the 
8-hour control requirements (65 FR 2674, January 18, 2000). We plan 
to complete rulemaking action on the 8-hour petitions at the time we 
lift the 8-hour stay. All of the States affected by the 1-hour and/
or 8-hour Section 126 Rule are also covered by the NOX 
SIP Call. The Section 126 Rule contains a provision under which the 
Section 126 findings and control requirements would be withdrawn if 
States have approved SIPs meeting the NOX SIP Call. The 
EPA has already withdrawn the 1-hour Section 126 Rule in three 
States and the District of Columbia and proposed to withdraw the 1-
hour rule in all other affected States except one. (We expect to 
propose action with respect to the rule in the remaining State 
shortly.)
---------------------------------------------------------------------------

    The draft regulatory text reflected the discussion in the June 
proposal.
    b. Summary of final rule. We are adopting the approach we set forth 
in our proposed rule and draft regulatory text. States must continue to 
adhere to the emission budgets established by the NOX 
transport rules after the 1-hour NAAQS is revoked. States retain the 
authority to revise control obligations they have established for 
specific sources or source categories under the NOX SIP Call 
rule so long as the State demonstrates consistent with section 110(l) 
that such modification will not interfere with attainment of or 
progress toward meeting the 8-hour NAAQS or any other applicable 
requirement of the CAA. We continue to believe that the reductions 
required by the NOX transport rules are necessary to address 
transported emissions for the 8-hour ozone NAAQS as well as the 1-hour 
ozone NAAQS.
    c. Comments and responses.
    (i) Comments on the June 2, 2003 proposal:
    Only a handful of commenters addressed this issue, all of whom 
supported the proposal. Several of these commenters recommended that we 
lift the stay of the NOX transport rules with respect to the 
8-hour NAAQS.

D. What Is the Required Timeframe for Obtaining Emissions Reductions To 
Ensure Attainment by the Attainment Date (Section VI.E of the Proposed 
Rule (68 FR 32826); Section 51.908 of the Draft and Final Rules)

1. Background
    In the June 2003 proposal, we proposed that emissions reductions 
needed for attainment must be implemented by an area's attainment date. 
We noted this meant that emissions reductions must be implemented by 
the beginning of the final ozone season prior to the attainment date. 
For example, for areas with an attainment date in May 2010, the 
emissions reductions need to be implemented by the beginning of the 
2009 ozone season because a determination of attainment will be based 
on air quality monitoring data from 2007, 2008 and 2009. The proposal 
cautioned that States should be aware of the consequences of failing to 
implement the control measures necessary for attainment sufficiently 
far in advance of their attainment date. As noted above, areas covered 
under subpart 2 can receive up to two 1-year attainment date extensions 
if certain criteria are met. However, if an area does not meet the 
eligibility requirements for the 1-year extension, it would be subject 
to a reclassification to a higher classification (bump up). While areas 
covered under subpart 1 are able to obtain up to two 1-year attainment 
date extensions, there is no provision for a bump up in subpart 1. If 
an area covered under subpart 1 fails to attain, section 179 of the CAA 
provides that EPA publish a finding of failure to attain which starts a 
1-year time frame for States to submit a SIP revision that provides for 
attainment within a specified time frame.
2. Summary of Final Rule
    In section 51.908, we are adopting the approach we set forth in our 
proposed rule, namely that emissions reductions needed for attainment 
must be implemented by the beginning of the ozone season immediately 
preceding the area's attainment date. We believe that Congress 
contemplated that control measures would continue to be implemented up 
to the attainment year. For example, section 182(c)(2)(B) requires 
areas classified as serious or higher to achieve an average of 3 
percent reduction in emissions per year over each 3-year period until 
the area's attainment date. If Congress intended areas to achieve all 
reductions needed for attainment 3 years prior to attainment, then the 
last 9 percent reductions required for serious and above areas would be 
reductions beyond those needed for attainment. We do not believe that 
Congress mandated these reductions in addition to the reductions needed 
to attain the NAAQS. In fact, this requirement is included in the 
statute as a part of the subparagraph addressing attainment and 
reasonable further progress, which indicates that Congress intended it 
to address progress toward attainment. This is further supported by the 
definition of reasonable further progress in section 171(1) as ``annual 
incremental reductions in emissions * * * for the purpose of ensuring 
attainment * * *.''
    Other provisions in the CAA also support the concept that areas do 
not need to achieve 3 years in advance of the attainment date the full 
complement of reductions needed for attainment. For example, Congress 
only provided marginal areas with 3 years to attain the NAAQS and did 
require at least minimal additional controls be implemented in such 
areas. In addition, the fact that Congress provided for two 1-year 
extensions of the attainment date also indicated that Congress believed 
that some areas might not be fully implementing all measures needed for 
attainment 3 years in advance of the attainment date. Rather, Congress 
contemplated that areas would have air quality healthy enough to make 
it substantially likely the area would attain within the next 1 or 2 
years.\44\
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    \44\ As discussed in the section regarding the two 1-year 
attainment date extensions, section 172(a)(2)(C), which applies to 
all pollutants, allows for a 1-year attainment date extension if the 
area has had ``minimal exceedances'' in the attainment year and 
section 181(a)(5), which applies to ozone nonattainment areas 
classified under subpart 2, allows for a 1-year extension if the 
area has had no more than 1 exceedance in the attainment year.
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    Finally, we note that the NAAQS itself does not contemplate that 
air quality must be at ``attainment levels'' for each of the 3 years on 
which attainment is based. Rather, attainment is determined based on an 
average of the 4th high reading at a monitor over a 3 year period. 
Thus, the 4th high reading for an area could be above the NAAQS for one 
or both of the years preceding the attainment year, but so long as the 
4th high level for the other year(s) was low enough to produce an 
average at or below 0.084 ppm, the area would be attaining the NAAQS.
    As noted in the June 2003 preamble, despite the fact that we 
believe an area need not have all controls implemented until the 
beginning of the final attainment season, the State needs to consider 
that attainment is based on a 3-year average. Thus, the State will need 
to ensure that implementation of controls is not unduly delayed. A 
State that plans to achieve reductions by the beginning of the ozone 
season prior to the attainment date may still experience meteorology 
conducive to very high ozone formation in that last ozone season that 
may result in the area having a 4th highest daily ozone concentration 
above the level of the 8-hour NAAQS, making it ineligible for the first 
of the 1-year extensions. Such an area--if classified under subpart 2--

[[Page 23990]]

would then be reclassified (bumped up) to a higher classification and 
be subject to additional planning requirements and mandatory control 
measures. Thus, a State should be aware of the consequences of delaying 
too long to implement control measures needed for attainment. 
Additionally, in reviewing implementation timeframes in SIPs, EPA will 
consider whether those timeframes are as expeditious as practicable. A 
guidance memorandum from John Seitz of November 30, 1999 \45\ 
reiterates the need to implement measures as expeditiously as 
practicable:
---------------------------------------------------------------------------

    \45\ Memorandum, ``Guidance on the Reasonably Available Control 
Measures (RACM) Requirement and Attainment Demonstration Submissions 
for Ozone Nonattainment Areas.'' John S. Seitz, Director, Office of 
Air Quality Planning and Standards. November 30, 1999. Web site: 
http://www.epa.gov/ttn/oarpg/t1pgm.html.

In order for EPA to determine whether an area has provided for 
implementation as expeditiously as practicable, the State must 
explain why the selected implementation schedule is the earliest 
schedule based on the specific circumstances of that area. Such 
claims cannot be general claims that more time is needed but rather 
should be specifically grounded in evidence of economic or 
technologic infeasibility. While it may be appropriate for some 
control measures to be implemented shortly after adoption, the EPA 
recognizes that other measures may need a longer period. The EPA 
will review the State's submission to ensure that sufficient 
information is provided for the EPA to determine whether the State 
has adopted all RACM necessary for attainment as expeditiously as 
practicable and provided for implementation of those measures as 
expeditiously as practicable. The EPA will make those determinations 
based on the information provided by the State and any other 
information available to the EPA at the time the Agency approves or 
disapproves the attainment demonstration.
3. Comments and Responses
    Comment: Some commenters agreed with our proposal as written, i.e., 
to require that emission reductions needed for attainment be 
implemented by the beginning of the ozone season prior to the 
attainment year.
    However, several commenters disagreed with the timeframe that was 
included in our proposal because it precludes areas from realizing the 
benefit of Federal measures prior to developing additional local 
controls.
    Another commenter stated that the attainment deadlines place an 
extraordinary burden on metropolitan areas to achieve the level of 
emissions reductions necessary to demonstrate attainment. The commenter 
felt that requiring emissions reductions to be implemented at the 
beginning of the ozone season prior to the attainment date is 1 year 
earlier than is required. The commenter stated that so long as there 
are no exceedances in the attainment year, i.e., having controls in 
place by the beginning of the ozone season of the attainment year, the 
area has met the statutory requirement and could qualify for the first 
of two 1-year attainment date extensions allowed under the CAA. The 
commenter further stated that controls for moderate areas would need to 
be in place by about the same time the area's SIP must be submitted to 
EPA in order to provide 3 years of clean data for the demonstration of 
attainment.
    Other commenters stated that all emissions reductions needed for 
attainment must be implemented in sufficient time to ensure attainment 
by the attainment date without relying on the CAA provisions for the 1-
year extensions.
    Response: Section 172(c)(2) of the CAA requires that emissions 
reductions needed for attainment be phased in such that RFP toward 
attainment is achieved. For areas classified as moderate under subpart 
2, their attainment date would be as expeditiously as practicable but 
no later than 6 years after the date of classification. Their ROP 
requirement would be at least a 15 percent VOC emissions reduction from 
the base year to be achieved no later than 6 years after the base year. 
However, if the area needed more than 15 percent VOC reductions in 
order to demonstrate attainment, then any additional reductions would 
also have to be achieved by the beginning of the ozone season prior to 
the area's attainment date.
    The CAA requires each area to demonstrate attainment as 
expeditiously as practicable but no later than the maximum timeframe 
specified in the CAA for the area. In addition, each area is required 
to adopt RACM. In determining whether measures are reasonably 
available, we consider cost, technical feasibility and whether 
implementation will advance the attainment date. An area cannot reject 
local control measures that are technically and economically feasible 
in favor of awaiting the implementation of national or regional 
controls, if to do so would delay attainment of the NAAQS. The 
consequences of failing to implement the control measures necessary for 
attainment sufficiently far in advance of the attainment date are 
discussed above and in the proposed rule.
    Areas covered under subpart 1 are also able to obtain up to two 1-
year extensions of the attainment date (see section 172(a)(2)(C)). 
There is no provision for bump-up in classification similar to that 
under subpart 2. However, if an area fails to attain, section 179 of 
the CAA provides that EPA publish a finding that the area failed to 
attain. The State then must submit within 1 year after that publication 
a revision to the SIP that provides for attainment within the time 
provided under section 179. Section 179 also provides that the SIP 
revision must also include any additional measures that EPA may 
prescribe.
    Comment: Several commenters suggested that nonattainment areas 
should be afforded the opportunity to install controls in time to 
monitor for attainment before the attainment deadline. The commenters 
believes that for many industrialized and metropolitan areas classified 
under Subpart 2 as marginal, moderate or serious, it will not be 
feasible to have stationary and mobile source controls in place 3 years 
before the attainment deadlines for the purposes of attainment 
monitoring. Pragmatically, state SIPS will not be finalized until mid-
2007, at which time industrial facilities can begin the 18-24 month 
period for detailed engineering, permitting and procurement of 
NOX control equipment. The installation of controls would 
occur over a 5-year average facility turnaround period. Furthermore, 
Tier II fuels and engines will just be entering the market as will 
cleaner diesel fuel and engines. It is virtually certain that many of 
these areas will not have the necessary emission reductions in place 3 
years before the attainment deadline and will be required to rely on 
the case-by-case extensions to the designated attainment deadlines. The 
commenters believe that Congress did not intend for EPA to establish 
attainment deadlines that would in a large number of cases 
automatically require areas to use deadline extensions; such areas have 
probably been misclassified. All nonattainment areas should be afforded 
the opportunity to install controls in time to monitor for attainment 
by the attainment deadline, but not three years prior to the attainment 
year. This would also eliminate the need for case-by-case extensions.
    Response: The final rule does not require emission reductions to be 
in place three ozone seasons prior to the attainment date. However, the 
after-the-fact determination of whether an area actually attains the 
NAAQS by its attainment date must be done by looking back at the 
previous 3 years of ambient air quality data. As noted elsewhere in 
this preamble, the CAA

[[Page 23991]]

provides for up to two 1-year extensions of the attainment date.
    Comment: Marginal areas may not be able to demonstrate compliance 
in 3 years and the final rule should provide for automatic extensions 
for such areas. Additional time to implement all of these reductions 
may be required in order for marginal areas to comply. By creating an 
automatic extension, EPA will avoid the inevitable cost of SIP 
nonattainment planning problems that communities will face if these 
measures are fully implemented.
    Response: The general assumption for marginal areas is that they 
will be able to attain without significant additional emissions 
controls. As such, section 182(a) specifies very little in terms of 
mandatory obligations for marginal areas. If an area needs additional 
controls and time to implement such controls, it may need to be 
reclassified to a higher classification. The CAA does not allow EPA to 
extend attainment dates for a classification.
    Comment: One commenter noted that EPA's proposal provides: ``For 
each nonattainment area, the State must provide for implementation of 
all control measures needed for attainment no later than the beginning 
of the attainment year ozone season.'' CAA Sec.  51.908(e). Attainment 
of the 8-hour NAAQS is based on analysis of 3 years of data. Part 51, 
App. I ] 2.3(a) (``The primary and secondary ozone ambient air quality 
standards are met at an ambient air quality monitoring site when the 3-
year average of the annual fourth highest daily maximum 8-hour average 
ozone concentration is less than or equal to 0.08 ppm.''). Thus, to 
meet the statutory requirement that SIPs provide for attainment, the 
rule must require SIPs to provide for implementation of all control 
measures needed for attainment no later than 3 years before the 
attainment date.
    Response: We disagree with the comment. In section 51.908, we are 
adopting the approach we set forth in our proposed rule, namely that 
emissions reductions needed for attainment must be implemented by the 
beginning of the ozone season immediately preceding the area's 
attainment date. Our rationale is presented above.
    Comment: In addition, a commenter stated that this timing was 
inconsistent with the draft modeling guidance which essentially 
requires areas with an attainment date of 2013 to have their controls 
in place by 2011 to perform an attainment demonstration. The 2011 date 
is inconsistent with the proposal which would require that the 
emissions reductions be in place in 2012. The commenter further stated 
that it seems inappropriate that the draft modeling guidance would be 
driving the schedule for implementation of control measures as opposed 
to the 8-hour implementation rule.
    Response: Comments on the modeling requirements will be addressed 
in Phase 2 of this rulemaking. The approach on when emission reductions 
needed for attainment must be in place was not based on the modeling 
requirements, but on the rationale stated in the preamble to the final 
rule. The modeling guidance will be revised for consistency with the 
final rule.

E. Conformity Under the 8-Hour Ozone Standard

    The June 2, 2003 proposal provided background discussion on issues 
related to transportation conformity and general conformity under the 
8-hour ozone standard. See sections VI.M (68 FR 32841) and VI.N. (68 FR 
32842). However, we did not propose any rules related to either. We did 
receive a number of comments on this topic, however. Responses to those 
comments are included in the response to comments document.

F. Comments on Other Issues

    We received comments on other issues associated with elements of 
this final rulemaking. We address those comments here. Comments on any 
other issues not discussed in this preamble or the RTC accompanying 
this final rule will be addressed in the second phase of this final 
rulemaking.
1. Designation of Nonattainment and Attainment Areas
    We received a number of comments on the designation process.
    Response: As we noted in the June 2, 2003 proposal, we did not 
propose to establish attainment/nonattainment designations nor did we 
address the principles that will be considered in the designation 
process; we issued guidance on the principles that States should 
consider in making designation recommendations in March 2000.\46\ The 
designation process is being conducted separately.
---------------------------------------------------------------------------

    \46\ EPA issued the memorandum ``Boundary Guidance on Air 
Quality Designations for the 8-Hour Ozone National Ambient Air 
Quality Standard (NAAQS or Standard)'' on March 28, 2000, from John 
S. Seitz, Director, Office of Air Quality Planning and Standards, to 
the Air Directors, Regions I-X, to provide guidance to State and 
local agencies and Tribes on designating areas and EPA's views on 
boundaries for nonattainment areas for the 8-hour NAAQS.
---------------------------------------------------------------------------

2. Early Action Compacts (EACs). (Section VIII.A.2. and 3 of the 
Proposal; See 68 FR 32859)
    We received a number of comments that addressed EACs. The June 2, 
2003 proposal included a description and background information 
concerning EACs, but the proposal made clear that we were not proposing 
any rulemaking on EACs in that notice.
    Response: The comments we received will be addressed in the rule 
that takes final action on the proposed rule to defer the effective 
date for EAC areas and therefore those comments are not addressed in 
this current rulemaking. We note that existing 1-hour maintenance areas 
will remain subject to all the requirements of that maintenance plan 
and transportation conformity, until the 1-hour standard is revoked 1 
year following the effective date of the area's 8-hour designation. If 
EPA takes final action deferring the effective date of the 8-hour 
designation for an EAC area, revocation of the 1-hour standard will 
also be effectively deferred for such area. Therefore, for such an EAC 
area that is a 1-hour maintenance area, the 1-hour maintenance plan, 
and 1-hour conformity, will continue to apply until 1 year after the 8-
hour designation takes effect.
3. Health and Environmental Concerns
    We received a number of general comments related to health and 
environmental concerns. Some of these cited national health statistics 
or provided information concerning the levels of ozone in their 
communities or information concerning the adverse health symptoms of 
themselves or friends, relatives, or patients. These commenters 
generally cited this information as a way of encouraging EPA to ensure 
expeditious attainment of the 8-hour ozone NAAQS and in some cases to 
support leaving the 1-hour NAAQS and its implementation process in 
place.
    Response: We have addressed these latter concerns above in 
discussion of the classification system, revocation of the 1-hour NAAQS 
and the anti-backsliding provisions that serve to ensure that the 8-
hour NAAQS is attained as expeditiously as practicable with little or 
no delay in emission reductions as a result of revoking the 1-hour 
NAAQS.
4. Clarity and Understandability of Proposed Rule
    A number of commenters expressed concern about the complexity of 
the proposed rule, and the lack of apparent

[[Page 23992]]

clarity and transparency. A number of these commenters complained that 
due to the large number of combinations of options that were possible 
from the proposal, it was difficult or impossible to determine exactly 
what the effect of the rule would be.
    Response: One of our principles in drafting the proposal was to 
make the rule as understandable as possible. However, the Supreme 
Court's ruling on our previous implementation approach left it to EPA 
to develop an implementation scheme with only general guidance as to 
how to proceed. Because the consequences of implementation under a 
particular approach might be fairly large, we felt obligated to place 
as many practicable options in our proposal as possible to assess 
public reaction by providing an opportunity for comment. This approach 
obviously added complexity to the proposal. We tried to minimize the 
complexity by setting forth two example frameworks for how some options 
could work in conjunction with each other. We also attempted in the 
draft regulatory text to focus on one set of options to illustrate how 
one set of options would work together. We attempted to simplify where 
we could and to provide other materials in the docket and on our web 
site for this rulemaking (e.g., the ``roadmap'' and the crosswalks 
between the June 2, 2003 proposal and the draft regulatory text) to 
enable the reader to more easily see relations between various sections 
of the proposal and to provide a synopsis of the options being 
proposed. Although the very nature of the proposal was complex, we 
believe that the public had sufficient opportunity to comment on the 
rule.
5. Regulatory Text
    A number of commenters chastised us for not providing regulatory 
text with the proposal.
    Response: As noted above, we did provide for public comment draft 
regulatory text, which reflected one set of proposed options. On August 
6, 2002 (68 FR 46536), we published a notice of availability of the 
draft regulatory text for the proposed rule to implement the 8-hour 
ozone NAAQS. This notice started a 30-day public comment period on the 
draft regulatory text.
6. Requests for Extension of Comment Periods
    We received a number of requests for extension of the comment 
periods on the three notices related to our proposal (the June 2, 2003 
proposal,\47\ the notice of availability of the draft regulatory 
text,\48\ and the notice reopening the comment period on the 
classification approach.\49\) We did not grant any of these 
requests.\50\ We provided a 60-day comment period on our full 
implementation proposal, which was published on June 2, 2003. We also 
provided a separate 30-day comment period on draft regulatory text 
(notice of availability was published on August 6, 2003). The October 
21, 2003 notice was very narrow, supplementing just one aspect of the 
June 2, 2003 proposal. We believe that a 15-day comment period was 
sufficient to address this limited issue. That notice was based on 
several comments which were submitted during the public comment period. 
Those comments have been available to the public since early August.
---------------------------------------------------------------------------

    \47\ OAR-2003-0079-0081, 0085 American Petroleum Institute (API) 
requests for extension to the August 1st, 2003 comment deadline.
    \48\ OAR-2003-0079-0405 Request for Extension of Time for Filing 
Comments on Draft Regulatory Text for Proposed Rule to Implement the 
8-Hour Ozone National Ambient Air Quality Standard (NAAQS) submitted 
by Howard J. Feldman, Director, American Petroleum Institute.
    \49\ OAR-2003-0079-0542, 0589, 0590 Request for Extension of 
time for 15-day comment period on approaches to implement the 8-hour 
ozone NAAQS, submitted by Gregory Dana, Vice President Environmental 
Affairs, Alliance of Automobile Manufacturers.
    OAR-2003-0079-0555 Request for extension of time for 15-day 
comment period on alternative approaches to implement the 8-hour 
ozone NAAQS submitted by Howard Feldman, Director Regulatory 
Analysis and Scientific Affairs, American Petroleum Institute (API).
    OAR-2003-0079-0572 Request for Extension of Public Comment 
Period submitted by Leslie S. Ritts, Counsel to The National 
Environmental Development Associations Clean Air Regulatory Project 
(NEDA/CARP).
    \50\ See, for instance, OAR-2003-0079-0165 Letter from S. Page, 
Director, OAQPS to H.J. Feldman, Director, API, denying extension of 
comment period.
---------------------------------------------------------------------------

    We are committed by a consent decree to designate areas for the 8-
hour ozone NAAQS by April 15, 2004. We believe it was essential to move 
forward to provide the public health protection that implementation of 
the 8-hour NAAQS will yield. We have recognized the strong interest 
from many stakeholders in our issuance of a final implementation rule 
prior to the April 2004 designation deadline. These interests, in 
conjunction with the reasons set forth above, support our denial of 
requests for an extension of the comment period. However, as is 
normally the case, we considered comments received after the close of 
the comment period to the extent we were able to do so without impeding 
the process for issuing the final rule.

G. Other Considerations

    Although Phase 2 of the final rule will address aspects of 
implementation of the 8-hour ozone NAAQS that are not addressed in this 
rulemaking, additional information is provided below regarding new 
source review for the 8-hour ozone NAAQS.
1. What Happens If a Source Is in the Process of PSD Permitting at the 
Time That the Area in Which It Is Located Is Designated as 
Nonattainment for the 8-Hour Ozone NAAQS?
    An area's designation at the time the final permit is issued 
determines which major New Source Review (NSR) requirements apply to 
the construction activity.
    Accordingly, if a source has received its PSD permit before the 
area is designated nonattainment, it may construct under the terms of 
that permit if it commences an ongoing program of construction within 
the required time period and completes the project within a reasonable 
time. However, if the area is designated nonattainment before the 
permit is issued (even if the reviewing authority deemed the PSD 
application complete), the PSD permit may not be issued. The source 
would be required to submit a new application to comply with the 
requirements of the applicable nonattainment major NSR program before 
receiving a final permit and beginning construction. 40 CFR 52.24(k) 
and 40 CFR part 51, appendix S. We have consistently applied this 
approach in past designation and redesignation situations.
    This approach is consistent with CAA section 165, which states that 
PSD permitting requirements apply only in attainment and unclassifiable 
areas. The DC District Court of Appeals affirmed this plain reading of 
the statute in the Alabama Power decision (636 F.2d 323). In response 
to EPA's attempt to apply PSD permitting requirements in some 
nonattainment areas, the court stated, ``After careful consideration of 
the statute and the legislative history, we must accept the contention 
of the industry petitioners that the phrase `constructed in any area to 
which this part applies' limits the application of section 165 to major 
emitting facilities to be constructed in [attainment and unclassifiable 
areas].'' The court went on to say, ``The plain meaning of the 
inclusion in section 165 of the words `any area to which this part 
applies' is that Congress intended location to be the key determinant 
of the applicability of the PSD review requirements.''
    This approach is also consistent with the regulatory text in the 
Federal PSD

[[Page 23993]]

regulations. These regulations limit the applicability of PSD 
requirements to ``an area designated as attainment or unclassifiable.'' 
40 CFR 51.166(a)(7)(i); 52.21(a)(2)(i).

H. EPA's Final Action

    We are taking final action on key elements of the program to 
implement the 8-hour ozone NAAQS. This final rule addresses the 
following topics: Classifications for the 8-hour NAAQS; revocation of 
the 1-hour NAAQS (i.e., when the 1-hour NAAQS will no longer apply); 
how anti-backsliding principles will ensure continued progress toward 
attainment of the 8-hour ozone NAAQS; attainment dates; and the timing 
of emission reductions needed for attainment. A summary of the rule 
appears in section IV of this preamble.

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 Office of Management and Budget (OMB) review 
and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or Tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Pursuant to the terms of Executive Order 12866, it has been 
determined that this rule is a ``significant regulatory action'' 
because it raises novel legal or policy issues arising out of legal 
mandates. As such, this action was submitted to OMB for review. Changes 
made in response to OMB suggestions or recommendations will be 
documented in the public record.

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
This rule merely interprets the requirement to develop State 
implementation plans to achieve a new or revised NAAQS. This 
requirement is prescribed in the CAA sections 110 and part D, subparts 
1 and 2 of Title 1. The present final rule does not establish any new 
information collection burden apart from any that required by law. A 
SIP contains rules and other requirements designed to achieve the NAAQS 
by the deadlines established under the CAA, and also contains a 
demonstration that the State's requirements will in fact result in 
attainment. Such a document is not considered information collection. 
Burden means the total time, effort, or financial resources expended by 
persons to generate, maintain, retain, or disclose or provide 
information to or for a Federal agency. This includes the time needed 
to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information. An agency may not 
conduct or sponsor, and a person is not required to respond to a 
collection of information unless it displays a currently valid OMB 
control number. The OMB control numbers for EPA's regulations in 40 CFR 
are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act generally requires an Agency to 
prepare a regulatory flexibility analysis of any rule subject to notice 
and comment rulemaking requirements under the Administrative Procedures 
Act or any other statute unless the Agency certifies 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 today's rule on small 
entities, small entity is defined as: (1) A small business that is a 
small industrial entity as defined in the U.S. Small Business 
Administration (SBA) size standards (See 13 CFR 121.); (2) a 
governmental jurisdiction that is a government of a city, county, town, 
school district or special district with a population of less than 
50,000; and (3) a small organization that is any not-for-profit 
enterprise which is independently owned and operated and is not 
dominant in its field.
    After considering the economic impacts of today's rule on small 
entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This rule 
will not impose any requirements on small entities. Rather, this rule 
interprets the obligations established in the CAA for States to submit 
implementation plans in order to attain the 8-hour ozone NAAQS. We are 
issuing this rule so that States and Tribes will know how we plan to 
classify areas and transition from implementation of the 1-hour NAAQS 
to implementation of the 8-hour NAAQS.

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 
1 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

[[Page 23994]]

proposals with significant Federal intergovernmental mandates, and 
informing, educating, and advising small governments on compliance with 
the regulatory requirements.
    The EPA has determined that 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 1 year. The estimated administrative burden hour and 
costs associated with implementing the 8-hour, 0.08 ppm NAAQS were 
developed upon promulgation of the NAAQS and presented in Chapter 10 of 
U.S. EPA 1997, Regulatory Impact Analyses for the Particulate Matter 
and Ozone National Ambient Air Quality Standards, Innovative Strategies 
and Economics Group, Office of Air Quality Planning and Standards, 
Research Triangle Park, NC, July 16, 1997. The estimated costs 
presented there for States in 1990 dollars totaled $0.9 million. The 
corresponding estimate in 1997 dollars is $1.1 million. Should the more 
traditional classification option be adopted as the implementation 
framework, these costs may increase modestly, but would not reach $100 
million. Thus, today's rule is not subject to the requirements of 
section 202 and 205 of the UMRA.
    The CAA imposes the obligation for States to submit SIPs to 
implement the 8-hour ozone NAAQS; in this rule, EPA is merely fleshing 
out those requirements. However, even if this rule did establish a 
requirement for States to submit SIPs, it is questionable whether a 
requirement 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 part D 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 section 421(5)(9a)(I) of UMRA (2 U.S.C. 658(a)(I)). Even if 
it did, the duty could be viewed as falling within the exception for a 
condition of Federal assistance under section 421(5)(a)(i)(I) of UMRA 
(2 U.S.C. 658(5)(a)(i)(I)).
    In this rule, EPA has determined that this rule contains no 
regulatory requirements that may significantly or uniquely affect small 
governments, including Tribal governments. Nonetheless, EPA carried out 
consultations with governmental entities affected by this rule.

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 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. As described in section D, above 
(on UMRA), EPA previously determined the costs to States to implement 
the 8-hour ozone NAAQS to be approximately $1 million. While this rule 
considers options not addressed at the time the NAAQS were promulgated, 
the costs for implementation under these options would may rise 
modestly. This rule fleshes out the statutory obligations of States in 
implementing the 8-hour ozone NAAQS. Finally, the CAA establishes the 
scheme whereby States take the lead in developing plans to meet the 
NAAQS. This rule would not modify the relationship of the States and 
EPA for purposes of developing programs to implement the NAAQS. Thus, 
Executive Order 13132 does not apply to this rule.
    Although section 6 of Executive Order 13132 does not apply to this 
rule, EPA actively engaged the States in the development of this rule. 
EPA held regular calls with representatives of State and local air 
pollution control agencies. EPA also held three public meetings at 
which it described the approaches it was considering and provided an 
opportunity for States and various other governmental officials to 
comment on the options being considered. Finally, EPA held three public 
hearings after the proposed rule was published to obtain public 
comments.

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

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 9, 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.'' This determination is stated 
below.
    This rule concerns the implementation of the 8-hour ozone NAAQS in 
areas designated nonattainment for that NAAQS. The CAA provides for 
States and Tribes to develop plans to regulate emissions of air 
pollutants within their jurisdictions. The regulations flesh out the 
statutory obligations of States and Tribes that develop plans to 
implement the 8-hour ozone NAAQS. The TAR gives Tribes the opportunity 
to develop and implement CAA programs such as the 8-hour ozone NAAQS, 
but it leaves to the discretion of the Tribe whether to develop these 
programs and which programs, or appropriate elements of a program, they 
will adopt.
    This rule does not have Tribal implications as defined by Executive 
Order 13175. It does not have a substantial direct effect on one or 
more Indian Tribes, since no Tribe has implemented a CAA program to 
attain the 8-hour ozone NAAQS at this time. Furthermore, this rule does 
not affect the relationship or distribution of power and 
responsibilities between the Federal government and Indian Tribes. The 
CAA and the TAR establish the relationship of the Federal government 
and Tribes in developing plans to attain the NAAQS, and this rule does 
nothing to modify that relationship. Because this rule does not have 
Tribal implications, Executive Order 13175 does not apply.
    The EPA also notes that even if Tribes choose to develop plans to 
implement the 8-hour ozone NAAQS in the future, these regulations would 
not impose substantial direct compliance costs on such Tribes, nor 
would they preempt Tribal law. As provided above, EPA has determined 
that the total costs for implementing the 8-hour ozone NAAQS by State, 
local, and Tribal governments is approximately $1 million in all areas 
designated nonattainment for the NAAQS. The percentage of Indian 
country that will be designated nonattainment for the 8-hour ozone 
NAAQS is very small. For Tribes that choose to regulate sources under 
their jurisdiction, the costs would be attributed to inspecting 
regulated facilities and enforcing adopted regulations.
    Although Executive Order 13175 does not apply to this rule, EPA did 
consult with Tribal officials in developing this rule and encouraged 
Tribal input at an

[[Page 23995]]

early stage. The EPA supports a national ``Tribal Designations and 
Implementation Work Group'' which provided an open forum for all Tribes 
to voice concerns to EPA about the designation and implementation 
process for the 8-hour ozone NAAQS. These discussions have given EPA 
valuable information about Tribal concerns regarding implementation of 
the 8-hour ozone NAAQS. The work group sent issue summaries and 
suggestions for addressing them to the newly formed National Tribal Air 
Association (NTAA), who in turn sent them to Tribal leaders. EPA 
encouraged Tribes to participate in the national public meetings held 
to take comment on early approaches to the rule. Several Tribes made 
public comments at the April 2002 public meeting in Tempe, Arizona.
    Furthermore, EPA sent individualized letters to all federally 
recognized Tribes about the proposal and gave Tribal leaders the 
opportunity for consultation. EPA received comment from the NTAA 
raising several questions: (1) NTAA asked for clarification on the 
nature of EPA's support for Tribes without Treatment in the same manner 
as a State (TAS) status and asked if EPA would provide technical 
assistance in interpreting SIP documentation to a Tribe without TAS 
approval; (2) NTAA asked EPA to explain how it envisions its role in 
continuing consultation with Tribes throughout the execution of SIPs. 
These comments will be addressed in the technical support document. The 
NTAA's final comment cited concerns with the impact of NSR requirements 
on the Tribes. The EPA intends to address these NSR comments in the 
Tribal NSR Rule.

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

    Executive Order 13045: ``Protection of Children From Environmental 
Health 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 
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.
    The rule is not subject to Executive Order 13045 because it 
implements a previously promulgated health based Federal standard (this 
rule implements the 8-hour ozone NAAQS). Nonetheless, we have evaluated 
the environmental health or safety effects of the 8-hour ozone NAAQS on 
children. The results of this evaluation are contained in 40 CFR part 
50, National Ambient Air Quality Standards for Ozone, Final Rule (62 FR 
38855-38896; specifically, 62 FR 38855, 62 FR 38860 and 62 FR 38865).

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

    This rule is not a ``significant energy action'' as defined in 
Executive Order 13211, ``Actions 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.
    Information on the methodology and data regarding the assessment of 
potential energy impacts is found in Chapter 6 of U.S. EPA 2003, Cost, 
Emission Reduction, Energy, and Economic Impact Assessment of the 
Proposed Rule Establishing the Implementation Framework for the 8-Hour, 
0.08 ppm Ozone National Ambient Air Quality Standard, prepared by the 
Innovative Strategies and Economics Group, Office of Air Quality 
Planning and Standards, Research Triangle Park, N.C. April 24, 2003.

I. National Technology Transfer Advancement Act

    Section 12(d) of the National Technology Transfer Advancement Act 
of 1995 (NTTAA), Public Law No. 104-113, section 12(d) (15 U.S.C. 272 
note) directs EPA to use voluntary consensus standards (VCS) 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 VCS bodies. The NTTAA directs EPA to provide Congress, 
through OMB, explanations when the Agency decides not to use available 
and applicable VCS.
    This rulemaking does not involve technical standards. Therefore, 
EPA is not considering the use of any VCS.
    The EPA will encourage the States and Tribes to consider the use of 
such standards, where appropriate, in the development of the 
implementation plans.

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

    Executive Order 12898 requires that each Federal agency make 
achieving environmental justice part of its mission by identifying and 
addressing, as appropriate, disproportionate high and adverse human 
health or environmental effects of its programs, policies, and 
activities on minorities and low-income populations.
    The EPA believes that this rule should not raise any environmental 
justice issues. The health and environmental risks associated with 
ozone were considered in the establishment of the 8-hour, 0.08 ppm 
ozone NAAQS. The level is designed to be protective with an adequate 
margin of safety. The rule provides a framework for improving 
environmental quality and reducing health risks for areas that may be 
designated nonattainment.

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. The 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 not a ``major rule'' as defined by 5 U.S.C. 
804(2). This rule will be effective June 15, 2004.

L. Petitions for Judicial Review

    Under section 307(b)(1) of the CAA, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the appropriate circuit by June 29, 2004. Filing a petition for 
reconsideration by the Administrator of this final rule does not affect 
the finality of this rule for the purposes of judicial review nor does 
it extend the time within which a petition for judicial review may be 
filed, and shall not postpone the effectiveness of such rule or action. 
This action may not be challenged later in proceedings to enforce its 
requirements. See CAA section 307(b)(2).

[[Page 23996]]

M. Determination Under Section 307(d)

    Pursuant to section 307(d)(1)(V) of the CAA, the Administrator 
determines that this action is subject to the provisions of section 
307(d). Section 307(d)(1)(V) provides that the provisions of section 
307(d) apply to ``such other actions as the Administrator may 
determine.'' While the Administrator did not make this determination 
earlier, the Administrator believes that all of the procedural 
requirements, e.g., docketing, hearing and comment periods, of section 
307(d) have been complied with during the course of this rulemaking.

Appendix A to Preamble--Example for 8-Hr Ozone Preamble Portion Dealing 
with Anti-Backsliding and Outstanding 1-Hr ROP Obligation

    Consider a 1-hour nonattainment area classified as Severe-15. 
For simplicity, only one precursor is assumed here, and this example 
does not account for issues of creditability established by the CAA. 
The 1-hour Severe-15 areas are required to reach attainment no later 
than 15 years after the 1990 base year, i.e., in year 2005. The ROP 
requirement over this 15-year period would be accomplished by an 
initial 15 percent reduction in emissions in the first six years, 
followed by additional 3 percent per year reductions (9 percent 
averaged over three years) until attainment is reached but no later 
than the attainment date (with any additional reductions needed for 
attainment). Suppose an area started with a base year emissions 
inventory of 1000 tons/day (t/d); after an initial 15 percent 
reduction, the area's emissions in 1996 would be 850 t/d. Subsequent 
additive linear 9 percent reductions would net 24 percent, 33 
percent, and 42 percent reductions, leaving emissions of 760 t/d in 
1999, 670 t/d in 2002, and 580 t/d in 2005. (Since each subsequent 9 
year incremental reduction toward attainment would have to account 
for adjustments in the base year inventory because of noncreditable 
reductions, actual reductions would vary somewhat from those shown 
here.)
    Assume that the same area is classified Serious for the 8-hour 
NAAQS. Under one of our proposed options for such an area, the area 
would be required to submit an RFP plan in 2006 that shows (for the 
6-year period from the end of 2002 to the end of 2008) an 18 percent 
reduction from a 2002 base year. The 1-hour NAAQS ROP schedule thus 
overlaps the 8-hour one, which begins in base year 2002 and 
continues to year 2013. As the same 1-hour Severe-15 area 
transitions to an 8-hour serious nonattainment area, overlap occurs 
during years 2002 through 2005. During this interval, the area will 
complete its last 9 percent incremental reduction in year 2005 for 
its 1-hour obligation while at the same time beginning to meet the 
8-hour obligation of 18 percent by 2008. Therefore, between 2002-
2005, the area will need to get (670 t/d-580 t/d =) 90 t/d 
reductions to meet its 1-hour obligation. The area would also be 
required to get between 2002--2008 an 18 percent reduction from the 
2002 base inventory of 670 t/d which equals a 121 t/d in reductions. 
However, since the 90 t/d is already obtained for the 2002-2005 
period, the area need only get an additional (121 t/d-90 t/d =) 31 
t/d reductions to meet the 8-hour obligation from 2005 out to 2008. 
Therefore, if this area had not actually submitted a 1-hour ROP plan 
that covered the 2002-2005 period, and it submitted its 8-hour RFP 
plan that achieves the 121 t/d reduction, it would be deemed to have 
met its 1-hour ROP obligation, provided that the RFP plan insured 
that 90 t/d would be achieved by 2005.

Appendix B to Preamble--Glossary of Terms and Acronyms

bump-up Reclassify to higher classification
CAA Clean Air Act
CAAA 1990 Clean Air Act Amendments
CFR Code of Federal Regulations
CMSA Consolidated Metropolitan Statistical Area
EAC Early Action Compacts
EPA Environmental Protection Agency
I/M Inspection and Maintenance Area
LAER Lowest achievable emission rate
LNB Low NOX Burner
MCR Mid-course review
MPO Metropolitan Planning Organization
NAAQS National Ambient Air Quality Standards
NOX Nitrogen oxides
NSR New source review
NTAA National Tribal Air Association
NTTAA National Technology Transfer Advancement Act of 1995
OMB Office of Management and Budget
OTR Ozone Transport Region
PAMS Photochemical Assessment Monitoring Stations
ppm Parts per million
PSD Prevention of significant deterioration
RACM Reasonably available control measures
RACT Reasonably available control technology
RFG Reformulated gasoline
RFP Reasonable further progress
ROP Rate of progress
SBA Small Business Administration
SCR Selective Catalytic Reduction
SIPs State implementation plans
TAR Tribal Authority Rule
TAS Treatment in the same manner as a State
t/d Tons per day
TEA-21 Transportation Equity Act for the Twenty-first Century
UMRA Unfunded Mandates Reform Act of 1995
VCS Voluntary consensus standards
VOC Volatile organic compound

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 51

    Air pollution control, Intergovernmental relations, Ozone, 
Particulate matter, Transportation, Volatile organic compounds.

40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
Wilderness areas.

    Authority: 42 U.S.C. 7408; 42 U.S.C. 7410; 42 U.S.C. 7501-7511f; 
42 U.S.C. 7601(a)(1); 42 U.S.C. 7401.

    Dated: April 15, 2004.
Michael O. Leavitt,
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 50.9 is amended by revising the second sentence of paragraph 
(b) to read as follows:


Sec.  50.9  National 1-hour primary and secondary ambient air quality 
standards for ozone.

* * * * *
    (b) * * * The 1-hour NAAQS set forth in paragraph (a) of this 
section will no longer apply to an area one year after the effective 
date of the designation of that area for the 8-hour ozone NAAQS 
pursuant to section 107 of the Clean Air Act. * * *
* * * * *

PART 51--REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF 
IMPLEMENTATION PLANS

0
3. The authority citation for Part 51 continues to read as follows:

    Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.


0
4. Part 51 is amended by adding a new subpart X to read as follows:

Subpart X--Provisions for Implementation of 8-hour Ozone National 
Ambient Air Quality Standard

Sec.
51.900 Definitions.
51.901 Applicability of part 51.
51.902 Which classification and area planning provisions of the CAA 
shall apply to areas designated nonattainment for the 8-hour NAAQS?
51.903 How do the classification and attainment date provisions in 
section 181 of subpart 2 of the CAA apply to areas subject to Sec.  
51.902(a)?
51.904 How do the classification and attainment date provisions in 
section

[[Page 23997]]

172(a) of subpart 1 of the CAA apply to areas subject to Sec.  
51.902(b)?
51.905 How do areas transition from the 1-hour NAAQS to the 8-hour 
NAAQS and what are the anti-backsliding provisions?
51.906 [Reserved]
51.907 For an area that fails to attain the 8-hour NAAQS by its 
attainment date, how does EPA interpret sections 172(a)(2)(C)(ii) 
and 181(a)(5)(B) of the CAA?
51.908 What is the required timeframe for obtaining emission 
reductions to ensure attainment by the attainment date?
51.909--51.916 [Reserved]

Subpart X--Provisions for Implementation of 8-hour Ozone National 
Ambient Air Quality Standard


Sec.  51.900  Definitions.

    The following definitions apply for purposes of this subpart. Any 
term not defined herein shall have the meaning as defined in 40 CFR 
51.100.
    (a) 1-hour NAAQS means the 1-hour ozone national ambient air 
quality standards codified at 40 CFR 50.9.
    (b) 8-hour NAAQS means the 8-hour ozone national ambient air 
quality standards codified at 40 CFR 50.10.
    (c) 1-hour ozone design value is the 1-hour ozone concentration 
calculated according to 40 CFR part 50, Appendix H and the 
interpretation methodology issued by the Administrator most recently 
before the date of the enactment of the CAA Amendments of 1990.
    (d) 8-Hour ozone design value is the 8-hour ozone concentration 
calculated according to 40 CFR part 50, appendix I.
    (e) CAA means the Clean Air Act as codified at 42 U.S.C. 7401--
7671q (2003).
    (f) Applicable requirements means for an area the following 
requirements to the extent such requirements apply or applied to the 
area for the area's classification under section 181(a)(1) of the CAA 
for the 1-hour NAAQS at the time the Administrator signs a final rule 
designating the area for the 8-hour standard as nonattainment, 
attainment or unclassifiable:
    (1) Reasonably available control technology (RACT).
    (2) Inspection and maintenance programs (I/M).
    (3) Major source applicability cut-offs for purposes of RACT.
    (4) Rate of Progress (ROP) reductions.
    (5) Stage II vapor recovery.
    (6) Clean fuels fleet program under section 183(c)(4) of the CAA.
    (7) Clean fuels for boilers under section 182(e)(3) of the CAA.
    (8) Transportation Control Measures (TCMs) during heavy traffic 
hours as provided under section 182(e)(4) of the CAA.
    (9) Enhanced (ambient) monitoring under section 182(c)(1) of the 
CAA.
    (10) Transportation controls under section 182(c)(5) of the CAA.
    (11) Vehicle miles traveled provisions of section 182(d)(1) of the 
CAA.
    (12) NOX requirements under section 182(f) of the CAA.
    (g) Attainment year ozone season shall mean the ozone season 
immediately preceding a nonattainment area's attainment date.
    (h) Designation for the 8-hour NAAQS shall mean the effective date 
of the 8-hour designation for an area.
    (i) Higher classification/lower classification. For purposes of 
determining whether a classification is higher or lower, 
classifications are ranked from lowest to highest as follows: 
classification under subpart 1 of the CAA; marginal; moderate; serious; 
severe-15; severe-17; and extreme.
    (j) Initially designated means the first designation that becomes 
effective for an area for the 8-hour NAAQS and does not include a 
redesignation to attainment or nonattainment for that standard.
    (k) Maintenance area for the 1-hour NAAQS means an area that was 
designated nonattainment for the 1-hour NAAQS on or after November 15, 
1990 and was redesignated to attainment for the 1-hour NAAQS subject to 
a maintenance plan as required by section 175A of the CAA.
    (l) Nitrogen Oxides (NOX) means the sum of nitric oxide 
and nitrogen dioxide in the flue gas or emission point, collectively 
expressed as nitrogen dioxide.
    (m) NOX SIP Call means the rules codified at 40 CFR 
51.121 and 51.122.
    (n) Ozone season means for each State, the ozone monitoring season 
as defined in 40 CFR Part 58, Appendix D, section 2.5 for that State.
    (o) Ozone transport region means the area established by section 
184(a) of the CAA or any other area established by the Administrator 
pursuant to section 176A of the CAA for purposes of ozone.
    (p) Reasonable further progress (RFP) means for the purposes of the 
8-hour NAAQS, the progress reductions required under section 172(c)(2) 
and section 182(b)(1) and (c)(2)(B) and (c)(2)(C) of the CAA.
    (q) Rate of progress (ROP) means for purposes of the 1-hour NAAQS, 
the progress reductions required under section 172(c)(2) and section 
182(b)(1) and (c)(2)(B) and (c)(2)(C) of the CAA.
    (r) Revocation of the 1-hour NAAQS means the time at which the 1-
hour NAAQS no longer apply to an area pursuant to 40 CFR 50.9(b).
    (s) Subpart 1 (CAA) means subpart 1 of part D of title I of the 
CAA.
    (t) Subpart 2 (CAA) means subpart 2 of part D of title I of the 
CAA.
    (u) Attainment Area means, unless otherwise indicated, an area 
designated as either attainment, unclassifiable, or attainment/
unclassifiable.


Sec.  51.901  Applicability of part 51.

    The provisions in subparts A through W of part 51 apply to areas 
for purposes of the 8-hour NAAQS to the extent they are not 
inconsistent with the provisions of this subpart.


Sec.  51.902  Which classification and nonattainment area planning 
provisions of the CAA shall apply to areas designated nonattainment for 
the 8-hour NAAQS?

    (a) Classification under subpart 2 (CAA). An area designated 
nonattainment for the 8-hour NAAQS with a 1-hour ozone design value 
equal to or greater than 0.121 ppm at the time the Administrator signs 
a final rule designating or redesignating the area as nonattainment for 
the 8-hour NAAQS will be classified in accordance with section 181 of 
the CAA, as interpreted in Sec.  51.903(a), for purposes of the 8-hour 
NAAQS, and will be subject to the requirements of subpart 2 that apply 
for that classification.
    (b) Covered under subpart 1 (CAA). An area designated nonattainment 
for the 8-hour ozone NAAQS with a 1-hour design value less than 0.121 
ppm at the time the Administrator signs a final rule designating or 
redesignating the area as nonattainment for the 8-hour NAAQS will be 
covered under section 172(a)(1) of the CAA and will be subject to the 
requirements of subpart 1.


Sec.  51.903  How do the classification and attainment date provisions 
in section 181 of subpart 2 of the CAA apply to areas subject to 
Sec. 51.902(a)?

    (a) In accordance with section 181(a)(1) of the CAA, each area 
subject to Sec.  51.902(a) shall be classified by operation of law at 
the time of designation. However, the classification shall be based on 
the 8-hour design value for the area, in accordance with Table 1 below, 
or such higher or lower classification as the State may request as 
provided in paragraphs (b) and (c) of this section. The 8-hour design 
value for the area shall be calculated using the three most recent 
years of air quality data. For each area classified under this section, 
the primary NAAQS attainment date for the 8-hour NAAQS shall be as 
expeditious as practicable but not later than the date provided in the 
following Table 1.

[[Page 23998]]



              Table 1.--Classification for 8-Hour Ozone NAAQS for Areas Subject to Sec.   51.902(a)
----------------------------------------------------------------------------------------------------------------
                                                                                            Maximum period for
                                                                                           attainment dates in
                                                                         8-hour  design     state plans (years
                Area class                                                 value  (ppm   after effective date of
                                                                             ozone)           nonattainment
                                                                                          designation for 8-hour
                                                                                                  NAAQS)
----------------------------------------------------------------------------------------------------------------
Marginal.................................  from........................           0.085                        3
                                           up to \1\...................           0.092
Moderate.................................  from........................           0.092                        6
                                           up to \1\...................           0.107
Serious..................................  from........................           0.107                        9
                                           up to \1\...................           0.120
Severe-15................................  from........................           0.120                       15
                                           up to \1\...................           0.127
Severe-17................................  from........................           0.127                       17
                                           up to \1\...................           0.187
Extreme..................................  equal to....................           0.187                      20
                                           or above....................
----------------------------------------------------------------------------------------------------------------
\1\ but not including.

    (b) A State may request a higher classification for any reason in 
accordance with section 181(b)(3) of the CAA.
    (c) A State may request a lower classification in accordance with 
section 181(a)(4) of the CAA.


Sec.  51.904  How do the classification and attainment date provisions 
in section 172(a) of subpart 1 of the CAA apply to areas subject to 
Sec.  51.902(b)?

    (a) Classification. The Administrator may classify an area subject 
to Sec.  51.902(b) as an overwhelming transport area if:
    (1) The area meets the criteria as specified for rural transport 
areas under section 182(h) of the CAA;
    (2) Transport of ozone and/or precursors into the area is so 
overwhelming that the contribution of local emissions to observed 8-
hour ozone concentration above the level of the NAAQS is relatively 
minor; and
    (3) The Administrator finds that sources of VOC (and, where the 
Administrator determines relevant, NOX) emissions within the 
area do not make a significant contribution to the ozone concentrations 
measured in other areas.
    (b) Attainment dates. For an area subject to Sec.  51.902(b), the 
Administrator will approve an attainment date consistent with the 
attainment date timing provision of section 172(a)(2)(A) of the CAA at 
the time the Administrator approves an attainment demonstration for the 
area.


Sec.  51.905  How do areas transition from the 1-hour NAAQS to the 8-
hour NAAQS and what are the anti-backsliding provisions?

    (a) What requirements that applied in an area for the 1-hour NAAQS 
continue to apply after revocation of the 1-hour NAAQS for that area? 
(1) 8-Hour NAAQS Nonattainment/1-Hour NAAQS Nonattainment. The 
following requirements apply to an area designated nonattainment for 
the 8-hour NAAQS and designated nonattainment for the 1-hour NAAQS at 
the time of designation for the 8-hour NAAQS for that area.
    (i) The area remains subject to the obligation to adopt and 
implement the applicable requirements as defined in Sec.  51.900(f), 
except as provided in paragraph (a)(1)(iii) of this section, and except 
as provided in paragraph (b) of this section.
    (ii) If the area has not met its obligation to have a fully-
approved attainment demonstration SIP for the 1-hour NAAQS, the State 
must comply with one of the following:
    (A) Submit a 1-hour attainment demonstration no later than 1 year 
after designation;
    (B) Submit a RFP plan for the 8-hour NAAQS no later than 1-year 
following designations for the 8-hour NAAQS providing a 5 percent 
increment of emissions reduction from the area's 2002 emissions 
baseline, which must be in addition to measures (or enforceable 
commitments to measures) in the SIP at the time of the effective date 
of designation and in addition to national or regional measures and 
must be achieved no later than 2 years after the required date for 
submission (3 years after designation).
    (C) Submit an 8-hour ozone attainment demonstration no later than 1 
year following designations that demonstrates attainment of the 8-hour 
NAAQS by the area's attainment date; provides for 8-hour RFP for the 
area out to the attainment date; and for the initial period of RFP for 
the area (between 2003-2008), achieve the emission reductions by 
December 31, 2007.
    (iii) If the area has an outstanding obligation for an approved 1-
hour ROP SIP, it must develop and submit to EPA all outstanding 1-hour 
ROP plans; where a 1-hour obligation overlaps with an 8-hour RFP 
requirement, the State's 8-hour RFP plan can be used to satisfy the 1-
hour ROP obligation if the 8-hour RFP plan has an emission target at 
least as stringent as the 1-hour ROP emission target in each of the 1-
hour ROP target years for which the 1-hour ROP obligation exists.
    (2) 8-Hour NAAQS Nonattainment/1-Hour NAAQS Maintenance. An area 
designated nonattainment for the 8-hour NAAQS that is a maintenance 
area for the 1-hour NAAQS at the time of designation for the 8-hour 
NAAQS for that area remains subject to the obligation to implement the 
applicable requirements as defined in Sec.  51.900 (f) to the extent 
such obligations are required by the approved SIP, except as provided 
in paragraph (b) of this section. Applicable measures in the SIP must 
continue to be implemented; however, if these measures were shifted to 
contingency measures prior to designation for the 8-hour NAAQS for the 
area, they may remain as contingency measures, unless the measures are 
required to be implemented by the CAA by virtue of the area's 
requirements under the 8-hour NAAQS. The State may not remove such 
measures from the SIP.
    (3) 8-Hour NAAQS Attainment/1-Hour NAAQS Nonattainment--(i) 
Obligations in an approved SIP. For an area that is 8-hour NAAQS 
attainment/1-hour NAAQS nonattainment, the State may request that 
obligations under the applicable requirements of Sec.  51.900(f) be 
shifted to contingency measures, consistent with sections 110(l) and 
193

[[Page 23999]]

of the CAA, after revocation of the 1-hour NAAQS; however, the State 
cannot remove the obligations from the SIP. For such areas, the State 
may request that the nonattainment NSR provisions be removed from the 
SIP on or after the date of revocation of the 1-hour NAAQS and need not 
be shifted to contingency measures subject to paragraph (e)(4) of this 
section.
    (ii) Attainment demonstration and ROP plans. (A) To the extent an 
8-hour NAAQS attainment/1-hour NAAQS nonattainment area does not have 
an approved attainment demonstration or ROP plan that was required for 
the 1-hour NAAQS under the CAA, the obligation to submit such an 
attainment demonstration or ROP plan
    (1) Is deferred for so long as the area continues to maintain the 
8-hour NAAQS; and
    (2) No longer applies once the area has an approved maintenance 
plan pursuant to paragraph (a)(3)(iii) of this section.
    (B) For an 8-hour NAAQS attainment/1-hour NAAQS nonattainment area 
that violates the 8-hour NAAQS, prior to having an approved maintenance 
plan for the 8-hour NAAQS as provided under paragraph (a)(3)(iii) of 
this section, paragraphs (a)(3)(ii)(B)(1), (2), and (3) of this section 
shall apply.
    (1) In lieu of any outstanding obligation to submit an attainment 
demonstration, within 1 year after the date on which EPA publishes a 
determination that a violation of the 8-hour NAAQS has occurred, the 
State must submit (or revise a submitted) maintenance plan for the 8-
hour NAAQS, as provided under paragraph (a)(3)(iii) of this section, 
to--
    (i) Address the violation by relying on modeling that meets EPA 
guidance for purposes of demonstrating maintenance of the NAAQS; or
    (ii) Submit a SIP providing for a 3 percent increment of emissions 
reductions from the area's 2002 emissions baseline; these reductions 
must be in addition to measures (or enforceable commitments to 
measures) in the SIP at the time of the effective date of designation 
and in addition to national or regional measures.
    (2) The plan required under paragraph (a)(3)(ii)(B)(1) of this 
section must provide for the emission reductions required within 3 
years after the date on which EPA publishes a determination that a 
violation of the 8-hour NAAQS has occurred.
    (3) The State shall submit an ROP plan to achieve any outstanding 
ROP reductions that were required for the area for the 1-hour NAAQS, 
and the 3-year period or periods for achieving the ROP reductions will 
begin January 1 of the year following the 3-year period on which EPA 
bases its determination that a violation of the 8-hour NAAQS occurred.
    (iii) Maintenance plans for the 8-hour NAAQS. For areas initially 
designated attainment for the 8-hour NAAQS, and designated 
nonattainment for the 1-hour NAAQS at the time of designation for the 
8-hour NAAQS, the State shall submit no later than 3 years after the 
area's designation for the 8-hour NAAQS, a maintenance plan for the 8-
hour NAAQS in accordance with section 110(a)(1) of the CAA. The 
maintenance plan must provide for continued maintenance of the 8-hour 
NAAQS for 10 years following designation and must include contingency 
measures. This provision does not apply to areas redesignated from 
nonattainment to attainment for the 8-hour NAAQS pursuant to CAA 
section 107(d)(3); such areas are subject to the maintenance plan 
requirement in section 175A of the CAA.
    (4) 8-Hour NAAQS Attainment/1-Hour NAAQS Maintenance--(i) 
Obligations in an approved SIP. For an 8-hour NAAQS attainment/1-hour 
NAAQS maintenance area, the State may request that obligations under 
the applicable requirements of Sec.  51.900(f) be shifted to 
contingency measures, consistent with sections 110(l) and 193 of the 
CAA, after revocation of the 1-hour NAAQS; however, the State cannot 
remove the obligations from the SIP.
    (ii) Maintenance Plans for the 8-hour NAAQS. For areas initially 
designated attainment for the 8-hour NAAQS and subject to the 
maintenance plan for the 1-hour NAAQS at the time of designation for 
the 8-hour NAAQS, the State shall submit no later than 3 years after 
the area's designation for the 8-hour NAAQS, a maintenance plan for the 
8-hour NAAQS in accordance with section 110(a)(1) of the CAA. The 
maintenance plan must provide for continued maintenance of the 8-hour 
NAAQS for 10 years following designation and must include contingency 
measures. This provision does not apply to areas redesignated from 
nonattainment to attainment for the 8-hour NAAQS pursuant to section 
107(d)(3); such areas are subject to the maintenance plan requirement 
in section 175A of the CAA.
    (b) Does attainment of the ozone NAAQS affect the obligations under 
paragraph (a) of this section? A State remains subject to the 
obligations under paragraphs (a)(1)(i) and (a)(2) of this section until 
the area attains the 8-hour NAAQS. After the area attains the 8-hour 
NAAQS, the State may request such obligations be shifted to contingency 
measures, consistent with sections 110(l) and 193 of the CAA; however, 
the State cannot remove the obligations from the SIP.
    (c) Which portions of an area designated for the 8-hour NAAQS 
remain subject to the obligations identified in paragraph (a) of this 
section? (1) Except as provided in paragraph (c)(2) of this section, 
only the portion of the designated area for the 8-hour NAAQS that was 
required to adopt the applicable requirements in Sec.  51.900(f) for 
purposes of the 1-hour NAAQS is subject to the obligations identified 
in paragraph (a) of this section, including the requirement to submit a 
maintenance plan for purposes of paragraph (a)(3)(iii) of this section. 
40 CFR Part 81, Subpart E identifies the boundaries of areas and the 
area designations and classifications for the 1-hour NAAQS at the time 
the 1-hour NAAQS no longer applied to each area.
    (2) For purposes of paragraph (a)(1)(ii)(B) and (C) of this 
section, the requirement to achieve emission reductions applies to the 
entire area designated nonattainment for the 8-hour ozone NAAQS.
    (d) [Reserved]
    (e) What obligations that applied for the 1-hour NAAQS will no 
longer apply after revocation of the 1-hour NAAQS for an area?--(1) 
Maintenance plans. Upon revocation of the 1-hour NAAQS, an area with an 
approved 1-hour maintenance plan under section 175A of the CAA may 
modify the maintenance plan: To remove the obligation to submit a 
maintenance plan for the 1-hour NAAQS 8 years after approval of the 
initial 1-hour maintenance plan; and to remove the obligation to 
implement contingency measures upon a violation of the 1-hour NAAQS. 
However, such requirements will remain enforceable as part of the 
approved SIP until such time as EPA approves a SIP revision removing 
such obligations. The EPA shall not approve a SIP revision requesting 
these modifications until the State submits and EPA approves an 
attainment demonstration for the 8-hour NAAQS for an area initially 
designated nonattainment for the 8-hour ozone NAAQS or a maintenance 
SIP for the 8-hour NAAQS for an area initially designated attainment 
for the 8-hour NAAQS. Any revision to such SIP must meet the 
requirements of section 110(l) and 193 of the CAA.
    (2) Findings of failure to attain the 1-hour NAAQS. (i) Upon 
revocation of the 1-hour NAAQS for an area, EPA is no longer 
obligated--
    (A) To determine pursuant to section 181(b)(2) or section 179(c) of 
the CAA

[[Page 24000]]

whether an area attained the 1-hour NAAQS by that area's attainment 
date for the 1-hour NAAQS; or
    (B) To reclassify an area to a higher classification for the 1-hour 
NAAQS based upon a determination that the area failed to attain the 1-
hour NAAQS by the area's attainment date for the 1-hour NAAQS.
    (ii) In addition, the State is no longer required to impose under 
CAA sections 181(b)(4) and 185 fees on emissions sources in areas 
classified as severe or extreme for failure to meet the 1-hour 
attainment date.
    (3) Conformity determinations for the 1-hour NAAQS. Upon revocation 
of the 1-hour NAAQS for an area, conformity determinations pursuant to 
section 176(c) of the CAA are no longer required for the 1-hour NAAQS. 
At that time, any provisions of applicable SIPs that require conformity 
determinations in such areas for the 1-hour NAAQS will no longer be 
enforceable pursuant to section 176(c)(5) of the CAA.
    (4) Nonattainment area new source review under the 1-hour NAAQS. 
(i) Upon revocation of the 1-hour ozone NAAQS, for any area that was 
designated nonattainment for the 1-hour ozone NAAQS, the area's 
implementation plan provisions satisfying sections 172(c)(5) and 173 of 
the CAA (including provisions satisfying section 182) based on the 
area's previous 1-hour ozone NAAQS classification are no longer 
required elements of an approvable implementation plan. Instead, the 
area's implementation plan must meet the requirements contained in 
paragraphs (e)(4)(ii) through (e)(4)(iv) of this section.
    (ii) If the area is designated nonattainment for the 8-hour ozone 
NAAQS, the implementation plan must include requirements to implement 
the provisions of sections 172(c)(5) and 173 of the CAA based on the 
area's 8-hour ozone NAAQS classification under part 81 of this chapter, 
and the provisions of Sec.  51.165.
    (iii) If the area is designated attainment or unclassifiable for 
the 8-hour ozone NAAQS, the area's implementation plan must include 
provisions to implement the provisions of section 165 of the CAA, and 
the provisions of Sec.  51.166 of this part, unless the provisions of 
Sec.  52.21 of this chapter apply in such area.
    (iv) If the area is designated attainment or unclassifiable but is 
located in an Ozone Transport Region, the area's implementation plan 
must include provisions to implement, consistent with the requirements 
in section 184 of the CAA, the requirements of sections 172(c) and 173 
of the CAA as if the area is classified as moderate nonattainment for 
the 8-hour ozone NAAQS.
    (f) What is the continued applicability of the NOX SIP 
Call after revocation of the 1-hour NAAQS? The NOX SIP Call 
shall continue to apply after revocation of the 1-hour NAAQS. Control 
obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 
may be modified by the State only if the requirements of Sec. Sec.  
51.121 and 51.122, including the statewide NOX emission 
budgets, continue to be met and the State makes a showing consistent 
with section 110(l) of the CAA.


Sec.  51.906  [Reserved]


Sec.  51.907  For an area that fails to attain the 8-hour NAAQS by its 
attainment date, how does EPA interpret sections 172(a)(2)(C)(ii) and 
181(a)(5)(B) of the CAA?

    For purposes of applying sections 172(a)(2)(C) and 181(a)(5) of the 
CAA, an area will meet the requirement of section 172(a)(2)(C)(ii) or 
181(a)(5)(B) of the CAA pertaining to 1-year extensions of the 
attainment date if:
    (a) For the first 1-year extension, the area's 4th highest daily 8-
hour average in the attainment year is 0.084 ppm or less.
    (b) For the second 1-year extension, the area's 4th highest daily 
8-hour value, averaged over both the original attainment year and the 
first extension year, is 0.084 ppm or less.
    (c) For purposes of paragraphs (a) and (b) of this section, the 
area's 4th highest daily 8-hour average shall be from the monitor with 
the highest 4th highest daily 8-hour average of all the monitors that 
represent that area.


Sec.  51.908  What is the required timeframe for obtaining emission 
reductions to ensure attainment by the attainment date?

    For each nonattainment area, the State must provide for 
implementation of all control measures needed for attainment no later 
than the beginning of the attainment year ozone season.


Sec. Sec.  51.909-51.916  [Reserved]

PART 81--DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES

0
5. The authority citation for Part 81 continues to read as follows:

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

0
6. Part 81 is amended by adding and reserving a new subpart E to read 
as follows:

Subpart E--Identification of Area Designations and Classifications 
for the 1-Hour Ozone NAAQS as of June 15, 2004 [Reserved]

[FR Doc. 04-9153 Filed 4-29-04; 8:45 am]
BILLING CODE 6560-50-P