Redesignation of the Columbus, OH Area to Attainment for the 8-Hour Ozone Standard, 32257-32266 [E7-11294]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 72, Number 112 (Tuesday, June 12, 2007)]
[Proposed Rules]
[Pages 32257-32266]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-11294]


-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R05-OAR-2007-0025; FRL-8326-3]


Redesignation of the Columbus, OH Area to Attainment for the 8-
Hour Ozone Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: The Ohio Environmental Protection Agency (Ohio EPA) submitted 
a request on December 28, 2006, and supplemented it on January 12, 2007 
and March 9, 2007, for redesignation of the Columbus, Ohio area which 
includes Delaware, Fairfield, Franklin, Knox, Licking, and Madison 
Counties to attainment for the 8-hour ozone standard. EPA is proposing 
to approve several elements associated with this request. First, EPA is 
making a determination that complete, quality-assured ambient air 
quality data indicate that the Columbus area has attained the 8-hour 
ozone standard. Second, EPA is proposing to approve, as revisions to 
the Ohio State Implementation Plan (SIP), the State's plans for 
maintaining the 8-hour ozone NAAQS through 2018. Third, EPA is 
proposing to redesignate the Columbus area to attainment for the 8-hour 
ozone standard, based on a finding that the requirements for this 
redesignation have been satisfied. Fourth, EPA finds adequate and is 
proposing to approve the State's 2009 and 2018 Motor Vehicle Emission 
Budgets (MVEBs) for the Columbus area.

DATES: Comments must be received on or before July 12, 2007.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2007-0001, by one of the following methods:
     https://www.regulations.gov/. Follow the on-line 
instructions for submitting comments.
     E-mail: mooney.john@epa.gov.
     Fax: (312)886-5824.
     Mail: John M. Mooney, Chief, Criteria Pollutant Section, 
Air Programs Branch, (AR-18J), U.S. Environmental Protection Agency, 77 
West Jackson Boulevard, Chicago, Illinois 60604.
     Hand delivery: John M. Mooney, Chief, Criteria Pollutant 
Section, Air Programs Branch, (AR-18J), U.S. Environmental Protection 
Agency, 77 West Jackson Boulevard, 18th floor, Chicago, Illinois 60604. 
Such deliveries are only accepted during the Regional Office normal 
hours of operation, and special arrangements should be made for 
deliveries of boxed information. The Regional Office official hours of 
business are Monday through Friday, 8:30 a.m. to 4:30 p.m. excluding 
Federal holidays.
    Instructions: Direct your comments to Docket ID No. EPA-R05-OAR-
2007-0001. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
www.regulations.gov, including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through www.regulations.gov or e-mail. 
The www.regulations.gov Web site is an ``anonymous access'' system, 
which means EPA will not know your identity or contact information 
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through www.regulations.gov, 
your e-mail address will be automatically captured and included as part 
of the comment that is placed in the public docket and made available 
on the Internet. If you submit an electronic comment, EPA recommends 
that you include your name and other contact information in the body of 
your comment and with any disk or CD-ROM you submit. If EPA cannot read 
your comment due to technical difficulties and cannot contact you for 
clarification, EPA may not be able to consider your comment. Electronic 
files should avoid the use of special characters, any form of 
encryption, and be free of any defects or viruses. For additional 
instructions on submitting comments, go to Section I of the 
SUPPLEMENTARY INFORMATION section of this document.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Environmental Protection 
Agency, Region 5, Air and Radiation Division, 77 West Jackson 
Boulevard, Chicago, Illinois 60604. This facility is open from 8:30 
a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. We 
recommend that you telephone Michael Leslie, Environmental Engineer, at 
(312) 353-6680 before visiting the Region 5 office.

FOR FURTHER INFORMATION CONTACT: Michael Leslie, Environmental 
Engineer, Criteria Pollutant Section, Air Programs Branch (AR-18J), 
Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, 
Chicago, Illinois 60604, (312) 353-6680, leslie.michael@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,'' 
``us,'' or ``our'' is used, we mean EPA. This supplementary information 
section is arranged as follows:

Table of Contents

I. What Should I Consider as I Prepare My Comments for EPA?
II. What Actions Is EPA Proposing To Take?
III. What Is the Background for These Actions?
IV. What Are the Criteria for Redesignation?
V. Why Is EPA Proposing To Take These Actions?

[[Page 32258]]

VI. What Is the Effect of These Actions?
VII. What Is EPA's Analysis of the Request?
    A. Attainment Determination and Redesignation
    B. Adequacy of Ohio's Motor Vehicle Emissions Budgets
VIII. What Actions Is EPA Taking Today?
IX. Statutory and Executive Order Reviews.

I. What Should I Consider as I Prepare My Comments for EPA?

    When submitting comments, remember to:
    1. Identify the rulemaking by docket number and other identifying 
information (subject heading, Federal Register date and page number).
    2. Follow directions--The EPA may ask you to respond to specific 
questions or organize comments by referencing a Code of Federal 
Regulations (CFR) part or section number.
    3. Explain why you agree or disagree; suggest alternatives and 
substitute language for your requested changes.
    4. Describe any assumptions and provide any technical information 
and/or data that you used.
    5. If you estimate potential costs or burdens, explain how you 
arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
    6. Provide specific examples to illustrate your concerns, and 
suggest alternatives.
    7. Explain your views as clearly as possible, avoiding the use of 
profanity or personal threats.
    8. Make sure to submit your comments by the comment period deadline 
identified.

II. What Actions Is EPA Proposing To Take?

    EPA is proposing to take several related actions. EPA is proposing 
to determine that the Columbus nonattainment area has attained the 8-
hour ozone standard. EPA is also proposing to approve Ohio's 
maintenance plan SIP revision for the Columbus area. The maintenance 
plan is designed to keep the Columbus nonattainment area in attainment 
of the ozone NAAQS through 2018. EPA is proposing the that Columbus 
area has met the requirements for redesignation under Section 
107(d)(3)(E) of the Clean Air Act (CAA). EPA is thus proposing to 
approve Ohio's request to change the legal determination of Columbus 
area from nonattainment to attainment for the 8-hour ozone National 
Ambient Air Quality Standard (NAAQS). Finally, EPA is announcing its 
action on the Adequacy Process for the newly established 2009 and 2018 
MVEBs for the area. The adequacy comment period for the 2009 and 2018 
MVEBs began on March 6, 2007, with EPA's posting of the availability of 
these submittals on EPA's Adequacy Web site (https://www.epa.gov/otaq/
stateresources/transconf/adequacy.htm). The adequacy comment period for 
these MVEBs ended on April 5, 2007. EPA did not receive any requests 
for these submittals or adverse comments on these submittals during the 
adequacy comment period. Therefore, we find adequate and are proposing 
to approve the State's 2009 and 2018 MVEBs for transportation 
conformity purposes.

III. What Is the Background for These Actions?

    On December 22, 2006, Ohio requested that EPA redesignate the 
Columbus area to attainment for the 8-hour ozone standard. The request 
was supplemented on January 12, 2007, and March 9, 2007. The 
redesignation request included three years of complete, quality-assured 
data for the periods of 2004 through 2006, indicating that the 8-hour 
NAAQS for ozone has been attained for the Columbus area. Under the CAA, 
nonattainment areas may be redesignated to attainment if sufficient 
complete, quality-assured data are available for the Administrator to 
determine that the area has attained the standard, and the area meets 
the other CAA redesignation requirements in section 107(d)(3)(E).

A. General Background Information

    EPA has determined that ground-level ozone is detrimental to human 
health. On July 18, 1997, EPA promulgated an 8-hour ozone NAAQS of 0.08 
parts per million parts of air (0.08 ppm) (80 parts per billion (ppb)) 
(62 FR 38856). This 8-hour ozone standard replaced a prior 1-hour ozone 
NAAQS, which had been promulgated on February 8, 1979 (44 FR 8202), and 
which was revoked on June 15, 2005 (69 FR 23858). Ground-level ozone is 
not emitted directly by sources. Rather, emitted NOX and VOC 
react in the presence of sunlight to form ground-level ozone along with 
other secondary compounds. NOX and VOC are referred to as 
``ozone precursors.'' Control of ground-level ozone concentrations is 
achieved through controlling VOC and NOX emissions.
    The CAA required EPA to designate as nonattainment any area that 
violated the 8-hour ozone NAAQS. The Federal Register notice 
promulgating these designations and classifications was published on 
April 30, 2004 (69 FR 23857).
    The CAA contains two sets of provisions--subpart 1 and subpart 2--
that address planning and emission control requirements for 
nonattainment areas. Both are found in title I, part D of the CAA. 
Subpart 1 contains general, less prescriptive requirements for all 
nonattainment areas for any pollutant governed by a NAAQS. Subpart 2 
contains more specific requirements for certain ozone nonattainment 
areas, and applies to ozone nonattainment areas classified under 
section 181 of the CAA.
    In the April 30, 2004, designation rulemaking, EPA divided 8-hour 
ozone nonattainment areas into the categories of subpart 1 
nonattainment (``basic'' nonattainment) and subpart 2 nonattainment 
(``classified'' nonattainment). EPA based this division on the area's 
8-hour ozone design values (i.e., on the three-year averages of the 
annual fourth-highest daily maximum 8-hour ozone concentrations at the 
worst-case monitoring sites in the areas) and on their 1-hour ozone 
design values (i.e., on the fourth-highest daily maximum 1-hour ozone 
concentrations over the three-year period at the worst-case monitoring 
sites in the areas). EPA classified 8-hour ozone nonattainment areas 
with 1-hour ozone design values equaling or exceeding 121 ppb as 
subpart 2, classified nonattainment areas. EPA classified all other 8-
hour nonattainment areas as subpart 1, basic nonattainment areas. The 
basis for area classification was explained in a separate April 30, 
2004, final rule (the Phase 1 implementation rule) (69 FR 23951).
    Emission control requirements for classified nonattainment areas 
are linked to area classifications. Areas with more serious ozone 
pollution problems are subject to more prescribed requirements and 
later attainment dates. The prescribed emission control requirements 
are designed to bring areas into attainment by their specified 
attainment dates.
    In the April 30, 2004, ozone designation/classification rulemaking, 
EPA designated the Columbus area as a subpart 1 basic nonattainment 
area for the 8-hour ozone NAAQS. EPA based the designation on ozone 
data collected during the 2001-2003 period.
    On December 22, 2006, the State of Ohio requested redesignation of 
Columbus area to attainment of the 8-hour ozone NAAQS based on ozone 
data collected in this area from 2004-2006.

B. What Is the Impact of the December 22, 2006, United States Court of 
Appeals Decision Regarding EPA's Phase 1 Implementation Rule?

1. Summary of Court Decision
    On December 22, 2006, the U.S. Court of Appeals for the District of 
Columbia

[[Page 32259]]

Circuit vacated EPA's Phase 1 Implementation Rule for the 8-hour Ozone 
Standard. (69 FR 23951, April 30, 2004). South Coast Air Quality 
Management Dist. v. EPA, 472 F.3d 882 (D.C. Cir. 2006). The Court held 
that certain provisions of EPA's Phase 1 Rule were inconsistent with 
the requirements of the CAA. The Court rejected EPA's reasons for 
implementing the 8-hour standard in nonattainment areas under Subpart 1 
in lieu of subpart 2 of Title I, part D of the Act. The Court also held 
that EPA improperly failed to retain four measures required for 1-hour 
nonattainment areas under the anti-backsliding provisions of the 
regulations: (1) Nonattainment area New Source Review (NSR) 
requirements based on an area's 1-hour nonattainment classification; 
(2) Section 185 penalty fees for 1-hour severe or extreme nonattainment 
areas; (3) measures to be implemented pursuant to section 172(c)(9) or 
182(c)(9) of the Act, on the contingency of an area not making 
reasonable further progress toward attainment of the 1-hour NAAQS, or 
for failure to attain that NAAQS; and (4) certain conformity 
requirements for certain types of Federal actions. The Court upheld 
EPA's authority to revoke the 1-hour standard provided there were 
adequate anti-backsliding provisions.
    This section sets forth EPA's views on the potential effect of the 
Court's ruling on this redesignation action. For the reasons set forth 
below, EPA does not believe that the Court's ruling alters any 
requirements relevant to this redesignation action so as to preclude 
redesignation, and does not prevent EPA from finalizing this 
redesignation. EPA believes that the Court's decision, as it currently 
stands, or as it may be modified based upon any petition for rehearing 
that has been filed, imposes no impediment to moving forward with 
redesignation of this area to attainment, because in either 
circumstance redesignation is appropriate under the relevant 
redesignation provisions of the Act and longstanding policies regarding 
redesignation requests.
2. Requirements Under the 8-Hour Standard
    With respect to the 8-hour standard, the Court's ruling rejected 
EPA's reasons for classifying areas under Subpart 1 for the 8-hour 
standard, and remanded that matter to the Agency. Consequently, it is 
possible that this area could, during a remand to EPA, be reclassified 
under Subpart 2. Although any future decision by EPA to classify this 
area under Subpart 2 might trigger additional future requirements for 
the area, EPA believes that this does not mean that redesignation 
cannot now go forward. This belief is based upon (1) EPA's longstanding 
policy of evaluating State submissions in accordance with the 
requirements due at the time the request is submitted; and, (2) 
consideration of the inequity of applying retroactively any future 
requirements.
    First, at the time the redesignation request was submitted, the 
Columbus area was classified under Subpart 1 and was obligated to meet 
Subpart 1 requirements. Under EPA's longstanding interpretation of 
section 107(d)(3)(E) of the CAA, to qualify for redesignation, States 
requesting redesignation to attainment must meet only the relevant SIP 
requirements that came due prior to the submittal of a complete 
redesignation request. September 4, 1992, Calcagni memorandum 
(``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' Memorandum from John Calcagni, Director, Air Quality 
Management Division) See also Michael Shapiro Memorandum, September 17, 
1993, and 60 FR 12459, 12465-66 (March 7, 1995) (Redesignation of 
Detroit--Ann Arbor). See Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 
2004), which upheld this interpretation. See, e.g. also 68 FR 25418, 
25424, 25427 (May 12, 2003) (redesignation of St. Louis).
    Moreover, it would be inequitable to retroactively apply any new 
SIP requirements that were not applicable at the time the request was 
submitted. The D.C. Circuit has recognized the inequity in such 
retroactive rulemaking, See Sierra Club v. Whitman, 285 F. 3d 63 (D.C. 
Cir. 2002), in which the D.C. Circuit upheld a District Court's ruling 
refusing to make retroactive an EPA determination of nonattainment that 
was past the statutory due date. Such a determination would have 
resulted in the imposition of additional requirements on the area. The 
Court stated: ``Although EPA failed to make the nonattainment 
determination within the statutory time frame, Sierra Club's proposed 
solution only makes the situation worse. Retroactive relief would 
likely impose large costs on the States, which would face fines and 
suits for not implementing air pollution prevention plans in 1997, even 
though they were not on notice at the time.'' Id. at 68. Similarly here 
it would be unfair to penalize the area by applying to it for purposes 
of redesignation additional SIP requirements under Subpart 2 that were 
not in effect at the time it submitted its redesignation request.
3. Requirements Under the 1-Hour Standard
    With respect to the requirements under the 1-hour standard, the 
Columbus area was an attainment area subject to a CAA section 175A 
maintenance plan under the 1-hour standard. The Court's ruling does not 
impact redesignation requests for these types of areas.
    First, there are no conformity requirements that are relevant for 
redesignation requests for any standard, including the requirement to 
submit a transportation conformity SIP. Under longstanding EPA policy, 
EPA believes that it is reasonable to interpret the conformity SIP 
requirement as not applying for purposes of evaluating a redesignation 
request under section 107(d) because State conformity rules are still 
required after redesignation and Federal conformity rules apply where 
State rules have not been approved. 40 CFR 51.390. See Wall v. EPA, 265 
F.3d 426 (6th Cir. 2001), upholding this interpretation. See also 60 FR 
62748 (Dec. 7, 1995) (Tampa, FL redesignation). Federal transportation 
conformity regulations apply in all States prior to approval of 
transportation conformity SIPs. The Columbus, Ohio 1-hour ozone area 
was redesignated to attainment without approved State transportation 
conformity regulations because the Federal regulations were in effect 
in Ohio. When challenged, these 1-hour ozone redesignations, which were 
approved without State regulations, were upheld by the courts. See Wall 
v. EPA, 265 F.3d 426 (6th Cir. 2001). See also 60 FR 62748 (December 7, 
1995) (Tampa, Florida). Although Ohio does not have approved State 
transportation conformity regulations, it has developed memoranda of 
understanding, signed by all parties involved in conformity, to address 
conformity consultation procedures. The Federal transportation 
conformity regulations, which apply in Ohio, require the approved 1-
hour ozone budgets to be used for transportation conformity purposes 
prior to 8-hour ozone budgets being approved.
    Second, with respect to the three other anti-backsliding provisions 
for the 1-hour standard that the Court found were not properly 
retained, Columbus area is an attainment area subject to a maintenance 
plan for the 1-hour standard, and the NSR, contingency measure 
(pursuant to section 172(c)(9) or 182(c)(9)) and fee provision 
requirements no longer apply to an area that has been redesignated to 
attainment of the 1-hour standard.

[[Page 32260]]

    Thus, the decision in South Coast should not alter requirements 
that would preclude EPA from finalizing the redesignation of this area.

IV. What Are the Criteria for Redesignation?

    Section 107(d)(3)(E) of the CAA allows for redesignation from 
nonattainment to attainment provided that: (1) The Administrator 
determines that the area has attained the applicable NAAQS; (2) the 
Administrator has fully approved the applicable implementation plan for 
the area under section 110(k); (3) the Administrator determines that 
the improvement in air quality is due to permanent and enforceable 
reductions in emissions resulting from implementation of the applicable 
SIP and applicable Federal air pollutant control regulations and other 
permanent and enforceable reductions; (4) the Administrator has fully 
approved a maintenance plan for the area as meeting the requirements of 
section 175A; and (5) the State containing such area has met all 
requirements applicable to the area under section 110 and part D.
    EPA provided guidance on redesignation in the General Preamble for 
the Implementation of Title I of the CAA Amendments of 1990, on April 
16, 1992 (57 FR 13498), and supplemented this guidance on April 28, 
1992 (57 FR 18070). EPA has provided further guidance on processing 
redesignation requests in several guidance documents. A listing of 
pertinent documents is provided in other redesignation actions 
including a September 9, 2005 notice; 70 FR 53606.

V. Why Is EPA Proposing To Take These Actions?

    On December 22, 2006, Ohio requested redesignation of the Columbus 
area to attainment for the 8-hour ozone standard. EPA believes that the 
area has attained the standard and has met the requirements for 
redesignation set forth in section 107(d)(3)(E) of the CAA.

VI. What Is the Effect of These Actions?

    Approval of the redesignation request would change the official 
designation of the Columbus area for the 8-hour ozone NAAQS found at 40 
CFR part 81. It would also incorporate into the Ohio SIP a plan for 
maintaining the 8-hour ozone NAAQS through 2018. The maintenance plans 
include contingency measures to remedy future violations of the 8-hour 
NAAQS. The maintenance plan also established MVEBs for the years 2009 
and 2018.

        Motor Vehicle Emissions Budgets for the Columbus, OH Area
------------------------------------------------------------------------
                                                VOC  (tons/  NOX  (tons/
                     Year                           day)         day)
------------------------------------------------------------------------
2009..........................................        72.16       125.43
2018..........................................        41.50        56.30
------------------------------------------------------------------------

    These proposed actions pertain to the designation of the Columbus 
area for the 8-hour ozone NAAQS and to the emission controls in the 
area related to the attainment and maintenance of the 8-hour ozone 
NAAQS. If you own or operate a VOC or NOX emissions source 
in this area or live in this area, this proposed rule may impact or 
apply to you. It may also impact you if you are involved in 
transportation planning or implementation of emission controls in this 
area. Finally, it may also impact you if you breathe the air in the 
Columbus area or the air which has passed through this area, or if you 
are concerned with clean air, human health or the environment.

VII. What Is EPA's Analysis of the Request?

A. Attainment Determination and Redesignation

    EPA is proposing to make a determination that the Columbus area has 
attained the 8-hour ozone standard and that the Columbus area has met 
all other applicable section 107(d)(3)(E) redesignation criteria. The 
basis for EPA's determinations is as follows:
1. The Area Has Attained the 8-Hour Ozone NAAQS (Section 
107(d)(3)(E)(i))
    EPA is proposing to make the determination that the Columbus area 
has attained the 8-hour ozone NAAQS. For ozone, an area may be 
considered to be attaining the 8-hour ozone NAAQS if there are no 
violations, as determined in accordance with 40 CFR 50.10 and Part 50, 
Appendix I, based on three complete, consecutive calendar years of 
quality-assured air quality monitoring data. For each monitor in the 
area, EPA computes the average of the fourth-highest daily maximum 8-
hour average ozone concentrations from each of the three most recent 
years. The area is attaining the standard if all monitors have average 
concentrations at or below 0.08 ppm. Based on the rounding convention 
described in 40 CFR Part 50, Appendix I, the standard is attained if 
the design value is 0.084 ppm or below. The data must be collected and 
quality-assured in accordance with 40 CFR part 58, and recorded in the 
Aerometric Information Retrieval System (AIRS). The monitors generally 
should have remained at the same location for the duration of the 
monitoring period required for demonstrating attainment.
    Ohio submitted 2004-2006 ozone monitoring data for the Columbus 
area. The Ohio EPA quality assured the ambient monitoring data in 
accordance with 40 CFR 58.10, and recorded it in the AIRS database, 
thus making the data publicly available. The data meet the completeness 
criteria in 40 CFR 50, Appendix I, which requires a minimum 
completeness of 75 percent annually and 90 percent over each three year 
period. A summary of the monitoring data is presented in Table 1 below.

Table 1.--Annual 4th High Daily Maximum 8-Hour Ozone Concentration and 3-Year Averages of 4th High Daily Maximum
                                           8-Hour Ozone Concentrations
----------------------------------------------------------------------------------------------------------------
                                                                                                      2004-2006
             Site ID                        County              2003 4th     2005 4th     2006 4th     average
                                                              high  (ppm)  high  (ppm)  high  (ppm)     (ppm)
----------------------------------------------------------------------------------------------------------------
39-041-0002.....................  Delaware..................           75           80           75           76
39-049-0028.....................  Franklin..................           75           86           76           79
39-049-0029.....................  Franklin..................           78           92           82           84
39-049-0037.....................  Franklin..................           73           86           79           79
39-049-0081.....................  Franklin..................           74           86           77           79
39-083-0002.....................  Knox......................           73           81           75           76
39-089-0005.....................  Licking...................           74           82           72           76
39-097-0007.....................  Madison...................           65           81           76           74
----------------------------------------------------------------------------------------------------------------


[[Page 32261]]

    In addition, as discussed below with respect to the maintenance 
plans, Ohio has committed to continue operating an EPA-approved 
monitoring network in accordance with 40 CFR part 58. In summary, EPA 
finds that the data submitted by Ohio provide an adequate demonstration 
that the Columbus area has attained the 8-hour ozone NAAQS.
2. The Area Has Met All Applicable Requirements Under Section 110 and 
Part D; and the Area Has a Fully Approved SIP Under Section 110(k) 
(Sections 107(d)(3)(E)(v) and 107(d)(3)(E)(ii))
    We have determined that Ohio has met all currently applicable SIP 
requirements for purposes of redesignation for the Columbus area under 
Section 110 of the CAA (general SIP requirements). We have also 
determined that the Ohio SIP meets all SIP requirements currently 
applicable for purposes of redesignation under Part D of Title I of the 
CAA (requirements specific to Subpart 1 nonattainment areas), in 
accordance with section 107(d)(3)(E)(v). In addition, we have 
determined that the SIP is fully approved with respect to all 
applicable requirements for purposes of redesignation, in accordance 
with section 107(d)(3)(E)(ii). In making these determinations, we have 
ascertained what SIP requirements are applicable to the area for 
purposes of redesignation, and have determined that the portions of the 
SIP meeting these requirements are fully approved under section 110(k) 
of the CAA. As discussed more fully below, SIPs must be fully approved 
only with respect to currently applicable requirements of the CAA.
a. Columbus, Ohio Has Met All Applicable Requirements Under Section 110 
and Part D of the CAA
    The September 4, 1992, Calcagni memorandum (see ``Procedures for 
Processing Requests To Redesignate Areas to Attainment,'' Memorandum 
from John Calcagni, Director, Air Quality Management Division, 
September 4, 1992) describes EPA's interpretation of section 
107(d)(3)(E) of the CAA. Under this interpretation, a State, and the 
area it wishes to redesignate, must meet the relevant CAA requirements 
that are due prior to the State's submittal of a complete redesignation 
request for the area. See also the September 17, 1993 Michael Shapiro 
memorandum and 60 FR 12459, 12465-66 (March 7, 1995) (redesignation of 
Detroit-Ann Arbor, Michigan to attainment of the 1-hour ozone NAAQS). 
Applicable requirements of the CAA that come due subsequent to the 
State's submittal of a complete request remain applicable until a 
redesignation to attainment is approved, but are not required as a 
prerequisite to redesignation. See section 175A(c) of the CAA. Sierra 
Club v. EPA, 375 F.3d 537 (7th Cir. 2004). See also 68 FR 25424, 25427 
(May 12, 2003) (redesignation of the St. Louis/East St. Louis area to 
attainment of the 1-hour ozone NAAQS).
    General SIP requirements. Section 110(a) of title I of the CAA 
contains the general requirements for a SIP. Section 110(a)(2) provides 
that the implementation plan submitted by a State must have been 
adopted by the State after reasonable public notice and hearing, and 
that, among other things, it includes enforceable emission limitations 
and other control measures, means or techniques necessary to meet the 
requirements of the CAA; provides for establishment and operation of 
appropriate devices, methods, systems and procedures necessary to 
monitor ambient air quality; provides for implementation of a source 
permit program to regulate the modification and construction of any 
stationary source within the areas covered by the plan; includes 
provisions for the implementation of part C, Prevention of Significant 
Deterioration (PSD) and part D, New Source Review (NSR) permit 
programs; includes criteria for stationary source emission control 
measures, monitoring, and reporting; includes provisions for air 
quality modeling; and provides for public and local agency 
participation in planning and emission control rule development.
    Section 110(a)(2)(D) of the CAA requires that SIPs contain measures 
to prevent sources in a State from significantly contributing to air 
quality problems in another State. To implement this provision, EPA has 
required certain States to establish programs to address transport of 
air pollutants (NOX SIP Call (63 FR 57356), Clean Air 
Interstate Rule (CAIR)(70 FR 25162)). However, the section 110(a)(2)(D) 
requirements for a State are not linked with a particular nonattainment 
area's designation and classification.
    EPA believes that the requirements linked with a particular 
nonattainment area's designation and classifications are the relevant 
measures to evaluate in reviewing a redesignation request. When the 
transport SIP submittal requirements are applicable to a State, they 
will continue to apply to the State regardless of the attainment 
designation of any one particular area in the State. Therefore, we 
believe that these requirements should not be construed to be 
applicable requirements for purposes of redesignation. Further, we 
believe that the other section 110 elements described above that are 
not connected with nonattainment plan submissions and not linked with 
an area's attainment status are also not applicable requirements for 
purposes of redesignation. A State remains subject to these 
requirements after an area is redesignated to attainment. We conclude 
that only the section 110 and part D requirements which are linked with 
a particular area's designation and classification are the relevant 
measures which we may consider in evaluating a redesignation request. 
This approach is consistent with EPA's existing policy on applicability 
of conformity and oxygenated fuels requirements for redesignation 
purposes, as well as with section 184 ozone transport requirements. See 
Reading, Pennsylvania, proposed and final rulemakings (61 FR 53174-
53176, October 10, 1996), (62 FR 24826, May 7, 1997); Cleveland-Akron-
Lorain, Ohio, final rulemaking (61 FR 20458, May 7, 1996); and Tampa, 
Florida, final rulemaking (60 FR 62748, December 7, 1995). See also the 
discussion on this issue in the Cincinnati ozone redesignation (65 FR 
37890, June 19, 2000), and in the Pittsburgh ozone redesignation (66 FR 
50399, October 19, 2001).
    As discussed above, we believe that section 110 elements which are 
not linked to the area's nonattainment status are not applicable for 
purposes of redesignation. Because there are no section 110 
requirements linked to the part D requirements for 8-hour ozone 
nonattainment areas that have become due, as explained below, there are 
no Part D requirements applicable for purposes of redesignation under 
the 8-hour standard.
    Part D Requirements. EPA has determined that the Ohio SIP meets 
applicable SIP requirements under part D of the CAA, since no 
requirements applicable for purposes of redesignation became due for 
the 8-hour ozone standard prior to Ohio's submission of the 
redesignation request for The Columbus area. Under part D, an area's 
classification determines the requirements to which it will be subject. 
Subpart 1 of part D, found in sections 172-176 of the CAA, sets forth 
the basic nonattainment requirements applicable to all nonattainment 
areas. Section 182 of the CAA, found in subpart 2 of part D, 
establishes additional specific requirements depending on the area's 
nonattainment classification. Columbus, Ohio, was classified as a 
subpart 1

[[Page 32262]]

nonattainment area, and, therefore, subpart 2 requirements do not 
apply.
    Part D, Subpart 1 applicable SIP requirements. For purposes of 
evaluating these redesignation requests, the applicable part D, subpart 
1 SIP requirements for the Columbus area are contained in sections 
172(c)(1)-(9).
    No 8-hour ozone planning requirements applicable for purposes of 
redesignation under part D became due prior to submission of the 
redesignation request, and, therefore, none are applicable to the area 
for purposes of redesignation. Since Ohio has submitted a complete 
ozone redesignation request for the Columbus area prior to the deadline 
for any submissions required for purposes of redesignation, we have 
determined that these requirements do not apply to the Columbus area 
for purposes of redesignation.
    Section 176 conformity requirements. Section 176(c) of the CAA 
requires States to establish criteria and procedures to ensure that 
Federally-supported or funded activities, including highway projects, 
conform to the air quality planning goals in the applicable SIPs. The 
requirement to determine conformity applies to transportation plans, 
programs and projects developed, funded or approved under Title 23 of 
the U.S. Code and the Federal Transit Act (transportation conformity) 
as well as to all other Federally-supported or funded projects (general 
conformity). State conformity revisions must be consistent with Federal 
conformity regulations relating to consultation, enforcement and 
enforceability, which EPA promulgated pursuant to CAA requirements.
    EPA approved Ohio's general and transportation conformity SIPs on 
March 11, 1996 (61 FR 9646) and May 30, 2000 (65 FR 34395), 
respectively. In summary, the Columbus area has satisfied all 
applicable requirements under section 110 and part D of the CAA.
b. Columbus Has a Fully Approved Applicable SIP Under Section 110(k) of 
the CAA
    EPA has fully approved the Ohio SIP for the Columbus area under 
section 110(k) of the CAA for all requirements applicable for purposes 
of redesignation. In approving a redesignation request, EPA may rely on 
prior SIP approvals plus any additional measures it may approve in 
conjunction with a redesignation action (See the September 4, 1992 John 
Calcagni memorandum, page 3, Southwestern Pennsylvania Growth Alliance 
v. Browner, 144 F.3d 984, 989-990 (6th Cir. 1998), Wall v. EPA, 265 
F.3d 426 (6th Cir. 2001)). Since the passage of the CAA of 1970, Ohio 
has adopted and submitted, and EPA has fully approved, provisions 
addressing the various required SIP elements applicable to the Columbus 
area under the 1-hour ozone standard. No Columbus area SIP provisions 
are currently disapproved, conditionally approved, or partially 
approved.
3. The Improvement in Air Quality Is Due to Permanent and Enforceable 
Reductions in Emissions (Section 107(d)(3)(E)(iii))
    EPA finds that Ohio has demonstrated that the observed air quality 
improvement in the Columbus area is due to permanent and enforceable 
reductions in emissions resulting from implementation of the SIP, 
Federal measures, and other State-adopted measures.
    In making this demonstration, the State has calculated the change 
in emissions between 2002 and 2004, one of the years in which the 
Columbus area monitored attainment. The reduction in emissions and the 
corresponding improvement in air quality over this time period can be 
attributed to a number of regulatory control measures that Ohio has 
implemented.
a. Permanent and Enforceable Controls Implemented
    The following is a discussion of permanent and enforceable measures 
that have been implemented in the area:
    NOX rules. In compliance with EPA's NOX SIP 
call, Ohio developed rules to control NOX emissions from 
Electric Generating Units (EGUs), major non-EGU industrial boilers, and 
major cement kilns. These rules required sources to begin reducing 
NOX emissions in 2004. However, statewide NOX 
emissions actually had begun to decline before 2004, as sources phased 
in emission controls needed to comply with the State's NOX 
emission control regulations. From 2004 on, NOX emissions 
from EGUs in the Eastern United States have been capped at a level well 
below pre-2002 levels, such that EGU emissions in the Columbus area, 
and elsewhere in Ohio, can be expected to remain well below 2002 
levels. Ohio expects that NOX emissions will further decline 
as the State meets the requirements of EPA's Phase II NOX 
SIP call (69 FR 21604 (April 21, 2004)).
    Federal Emission Control Measures. Reductions in VOC and 
NOX emissions have occurred statewide as a result of Federal 
emission control measures, with additional emission reductions expected 
to occur in the future as the State implements additional emission 
controls. Federal emission control measures include: Tier 2 emission 
standards for vehicles, gasoline sulfur limits, low sulfur diesel fuel 
standards, and heavy-duty diesel engine standards. In addition, in 
2004, EPA issued the Clean Air Non-road Diesel Rule (69 FR 38958 (July 
29, 2004)). EPA expects this rule to reduce off-road diesel emissions 
through 2010, with emission reductions starting in 2008.
b. Emission Reductions.
    Ohio is using 2002 for the nonattainment inventory and included 
area, mobile and point source emissions. Area sources were taken from 
the Ohio 2002 periodic inventory submitted to EPA. These projections 
were made from the United States Department of Commerce Bureau of 
Economic Analysis growth factors, with some updated local information. 
Mobile source emissions were calculated from MOBILE6.2 produced 
emission factors. Non-road emissions were generated using the EPA's 
National Mobile Inventory Model (NMIM) 2002 application. Point source 
information was compiled from Ohio's 2002 annual emission inventory 
database and the 2002 EPA Clean Air Markets Acid Rain database.
    Based on the inventories described above, Ohio's submittal 
documents changes in VOC and NOX emissions from 2002 to 
2004. Summaries of emissions data are shown in Tables 2 through 4.

       Table 2.--The Columbus Area Total VOC and NOX Emissions for
                   Nonattainment Year 2002 (Tons/Day)
------------------------------------------------------------------------
                      Sector                           VOC        NOX
------------------------------------------------------------------------
Point.............................................       5.39      10.71
Area..............................................      65.15       6.84
Non-Road Mobile...................................      28.55      41.90
On-Road Mobile....................................      97.84     163.94
                                                   ---------------------
    Columbus Area Total...........................     196.93     223.39
------------------------------------------------------------------------


 Table 3.--The Columbus Area Total VOC and NOX Emissions for Attainment
                          Year 2004 (Tons/Day)
------------------------------------------------------------------------
                      Sector                           VOC        NOX
------------------------------------------------------------------------
Point.............................................       5.05      10.30
Area..............................................      64.75       7.18
Non-Road Mobile...................................      26.20      38.73
On-Road Mobile....................................      87.84     150.89
                                                   ---------------------
    Columbus Area Total...........................     183.84     207.10
------------------------------------------------------------------------


[[Page 32263]]


         Table 4.--The Columbus, Ohio Area: Comparison of 2002 and 2004 VOC and NOX Emissions (Tons/Day)
----------------------------------------------------------------------------------------------------------------
                                                     VOC                                    NOX
                                   -----------------------------------------------------------------------------
              Sector                                           Net change                             Net change
                                        2002         2004     (2002-2004)      2002         2004     (2002-2004)
----------------------------------------------------------------------------------------------------------------
Point.............................         5.39         5.05        -0.24        10.71        10.30        -0.41
Area..............................        65.15        64.75        -0.40         6.84         7.18         0.34
Nonroad...........................        28.55        26.20        -2.35        41.90        38.73        -3.17
Onroad............................        97.84        87.84       -10.00       163.94       150.89       -13.05
                                   -----------------------------------------------------------------------------
    Total.........................       196.93       183.84       -13.09       223.39       207.10       -16.29
----------------------------------------------------------------------------------------------------------------

    Table 4 shows that the area reduced VOC emissions by 13.09 tons/
day, and NOX emissions by 16.29 tons/day, between 2002 and 
2004. Based on the information summarized above, Ohio has adequately 
demonstrated that the improvement in air quality is due to permanent 
and enforceable emissions reductions.
4. The Area Has a Fully Approved Maintenance Plan Pursuant to Section 
175a of the CAA (Section 107(d)(3)(E)(iv))
    In conjunction with its request to redesignate the Columbus area to 
attainment status, Ohio submitted SIP revisions to provide for the 
maintenance of the 8-hour ozone NAAQS in this area through 2018.
a. What is required in a maintenance plan?
    Section 175A of the CAA sets forth the required elements of a 
maintenance plan for areas seeking redesignation from nonattainment to 
attainment. Under section 175A, the plan must demonstrate continued 
attainment of the applicable NAAQS for at least ten years after the 
Administrator approves a redesignation to attainment. Eight years after 
the redesignation, the State must submit a revised maintenance plan 
which demonstrates that attainment will continue to be maintained for 
ten years following the initial ten-year maintenance period. To address 
the possibility of future NAAQS violations, the maintenance plan must 
contain contingency measures with a schedule for implementation as EPA 
deems necessary to assure prompt correction of any future 8-hour ozone 
violations.
    The September 4, 1992, John Calcagni memorandum provides additional 
guidance on the content of a maintenance plan. The memorandum clarifies 
that an ozone maintenance plan should address the following items: The 
attainment VOC and NOX emissions inventories, a maintenance 
demonstration showing maintenance for the ten years of the maintenance 
period, a commitment to maintain the existing monitoring network, 
factors and procedures to be used for verification of continued 
attainment of the NAAQS, and a contingency plan to prevent or correct 
future violations of the NAAQS.
b. Attainment Inventory
    Ohio developed a baseline emissions inventory for 2004, one of the 
years used to demonstrate monitored attainment of the 8-hour NAAQS. The 
attainment level of emissions is summarized in Table 3, above.
c. Demonstration of Maintenance
    Ohio submitted revisions to the 8-hour ozone SIP to include 11-year 
maintenance plans for the Columbus area, in compliance with section 
175A of the CAA. This demonstration shows maintenance of the 8-hour 
ozone standard by assuring that current and future emissions of VOC and 
NOX area remain at or below attainment year emission levels. 
A maintenance demonstration need not be based on modeling. See Wall v. 
EPA, 265 F.3d 426 (6th Cir. 2001), Sierra Club v. EPA, 375 F. 3d 537 
(7th Cir. 2004). See also 66 FR 53094, 53099-53100 (October 19, 2001), 
68 FR 25413, 25430-25432 (May 12, 2003).
    Ohio is using projected inventories for the years 2009 and 2018. 
These emission estimates are presented in Table 5.

           Table 5.--The Columbus, Ohio Area: Comparison of 2004-2018 VOC and NOX Emissions (Tons/Day)
----------------------------------------------------------------------------------------------------------------
                                                 VOC                                       NOX
                             -----------------------------------------------------------------------------------
           Sector                                           Net change                                Net change
                                2004      2009      2018     2004-2018    2004      2009      2018     2004-2018
----------------------------------------------------------------------------------------------------------------
Point.......................      5.05      4.43      5.20        0.15     10.30      9.38     10.00       -0.30
Area........................     64.75     63.75     67.24        2.49      7.18      8.06      8.60        1.42
Nonroad.....................     26.20     20.28     18.85       -7.35     38.73     30.72     20.14      -18.59
Onroad......................     87.84     62.76     36.09      -51.75    150.89    109.07     49.01     -101.88
                             -----------------------------------------------------------------------------------
    Total...................    183.84    151.22    127.38      -56.46    207.10    157.23     87.75     -119.35
----------------------------------------------------------------------------------------------------------------

    The emission projections show that Ohio does not expect emissions 
in the area to exceed the level of the 2004 attainment year inventory 
during the maintenance period. In the area, Ohio projects that VOC and 
NOX emissions will decrease by 56.46 tons/day and 119.35 
tons/day, respectively.
    As part of its maintenance plan, the State elected to include a 
``safety margin'' for the area. A ``safety margin'' is the difference 
between the attainment level of emissions (from all sources) and the 
projected level of emissions (from all sources) in the maintenance plan 
which continues to demonstrate attainment of the standard. The 
attainment level of emissions is the level of emissions during one of 
the years in which the area met the NAAQS. Ohio used 2004 as the 
attainment level

[[Page 32264]]

of emissions for the area. In the maintenance plan, Ohio projected 
emission levels for 2018. The emissions from point, area, non-road, and 
mobile sources in 2004 equaled 183.84 tons/day of VOC and 207.10 tons/
day of NOX. Ohio projected VOC emissions for the year 2018 
to be 127.38 tons/day of VOC and 87.75 tons/day of NOX. The 
safety margin is calculated to be the difference between these amounts 
or, in this case, 56.46 tons/day of VOC and 119.35 tons/day of 
NOX for 2018. The safety margin, or a portion thereof, can 
be allocated to any of the source categories, as long as the total 
attainment level of emissions is maintained. Ohio EPA allocated 5.41 
tons/day of VOC and 7.35 tons/day of NOX to the MVEB. The 
SIP submission demonstrates that the area will continue to maintain the 
standard because emission will continue to be below the attainment 
level.
d. Monitoring Network
    Ohio currently operates eight ozone monitors in the Columbus area. 
Ohio has committed to continue operating and maintaining their approved 
ozone monitor network in accordance with 40 CFR part 58.
e. Verification of Continued Attainment
    Continued attainment of the ozone NAAQS in the area depends, in 
part, on the State's efforts toward tracking indicators of continued 
attainment during the maintenance period. The State's plan for 
verifying continued attainment of the 8-hour standard in the area 
consists of plans to continue ambient ozone monitoring in accordance 
with the requirements of 40 CFR part 58. In addition, Ohio will 
periodically review and revise the VOC and NOX emissions 
inventories for the area, as required by the Consolidated Emissions 
Reporting Rule (40 CFR part 51), to track levels of emissions in the 
future.
f. Contingency Plan
    The contingency plan provisions of the CAA are designed to result 
in prompt correction or prevention of violations of the NAAQS that 
might occur after redesignation of an area to attainment of the NAAQS. 
Section 175A of the CAA requires that a maintenance plan include such 
contingency measures as EPA deems necessary to assure that the State 
will promptly correct a violation of the NAAQS that might occur after 
redesignation. The maintenance plan must identify the contingency 
measures to be considered for possible adoption, a schedule and 
procedure for adoption and implementation of the selected contingency 
measures, and a time limit for action by the State. The State should 
also identify specific indicators to be used to determine when the 
contingency measures need to be adopted and implemented. The 
maintenance plan must include a requirement that the State will 
implement all measures with respect to control of the pollutant(s) that 
were included in the SIP before the redesignation of the area to 
attainment. See section 175A(d) of the CAA.
    As required by section 175A of the CAA, Ohio has adopted a 
contingency plan to address possible future ozone air quality issues. 
The contingency plan has two levels of actions/responses depending on 
whether a violation of the 8-hour ozone standard is only threatened 
(Warning Level Response) or has actually occurred or appears to be very 
imminent (Action Level Response).
    A Warning Level Response will be triggered whenever an annual (1-
year) fourth-high monitored 8-hour ozone concentration of 88 ppb occurs 
within the ozone maintenance area (Columbus area). A Warning Level 
Response will consist of a study to determine whether the ozone value 
indicates a trend toward higher ozone concentrations or whether 
emissions appear to be increasing. The study will evaluate whether the 
trend, if any, is likely to continue and, if so, the control measures 
necessary to reverse the trend, taking into consideration ease and 
timing for implementation, as well as economic and social 
consideration. Implementation of necessary controls in response to a 
Warning Level Response triggering will take place as expeditiously as 
possible, but in no event later than 12 months from the conclusion of 
the most recent ozone season.
    An Action Level Response will be triggered whenever a two-year 
average annual fourth-high monitored 8-hour ozone concentration of 85 
ppb or greater occurs within the maintenance area (Columbus area). A 
violation of the 8-hour ozone standard (three-year average fourth-high 
value of 85 ppb or greater) will also prompt an Action Level Response. 
In the event that an Action Level Response is triggered and is not due 
to an exceptional event, malfunction, or noncompliance with a source 
permit condition or rule requirement, Ohio will determine the 
additional emission control measures needed to assure future attainment 
of the ozone NAAQS. Emission control measures that can be implemented 
in a short time will be selected in order to be in place within 18 
months from the close of the ozone season that prompted the Action 
Level Response. Any new emission control measure that is selected for 
implementation will be given a public review. If a new emission control 
measure is already promulgated and scheduled to be implemented at the 
Federal or State level and that emission control measure is determined 
to be sufficient to address the increase in peak ozone concentrations, 
additional local measures may be unnecessary. Ohio will submit to the 
EPA an analysis to assess whether the proposed emission control 
measures are adequate to reverse the increase in peak ozone 
concentrations and to maintain the 8-hour ozone standard in the area. 
The selection of emission control measures will be based on cost-
effectiveness, emission reduction potential, economic and social 
considerations, or other factors that Ohio deems to be appropriate. 
Selected emission control measures will be subject to public review and 
the State will seek public input prior to selecting new emission 
control measures.
    The State's ozone redesignation request lists the following 
possible emission control measures as contingency measures in the ozone 
maintenance portion of the State's submittal:
    i. Lower Reid vapor pressure gasoline requirements;
    ii. Tighten RACT on existing source covered by USEPA Control 
Techniques Guidelines issued in response to the 1990 CAA;
    iii. Apply RACT to smaller existing sources;
    iv. One or more transportation control measures sufficient to 
achieve at least half a percent reduction in actual area wide VOC 
emissions. Transportation-measures will be selected from the following, 
based upon the factors listed above after consultation with affected 
local governments:
    a. Trip reduction programs, including, but not limited to, 
employer-based transportation management plans, area-wide rideshare 
programs, work schedule changes, and telecommuting;
    b. Traffic flow and transit improvements; and
    c. Other new or innovative transportation measures not yet in 
widespread use that affects State and local governments deemed 
appropriate.
    v. Alternative fuel and diesel retrofit programs for fleet vehicle 
operations.
    vi. Controls on consumer products consistent with those adopted 
elsewhere in the United States.
    vii. Require VOC and NOX emissions offsets for new and 
modified major sources.

[[Page 32265]]

    viii. Require VOC or NOX emission offsets for new or 
modified minor sources.
    ix. Increase the ratio of emission offsets required for new 
sources.
    x. Require VOC or NOX controls on new minor sources 
(less than 100 tons).
    g. Provisions for Future Updates of the Ozone Maintenance Plan.
    As required by section 175A(b) of the CAA, Ohio commits to submit 
to the EPA updated ozone maintenance plans eight years after 
redesignation to cover an additional 10-year period beyond the initial 
10-year maintenance period. Ohio has committed to retain the control 
measures for VOC and NOX emissions that were contained in 
the SIP before redesignation of the area to attainment, as required by 
section 175(A) of the CAA.
    EPA proposes that the maintenance plan adequately addresses the 
five basic components of a maintenance plan: attainment inventory, 
maintenance demonstration, monitoring network, verification of 
continued attainment, and a contingency plan.

B. Adequacy of Ohio's Motor Vehicle Emissions Budgets (MVEBs)

1. How Are MVEBs Developed and What Are the MVEBs for the Area?
    Under the CAA, States are required to submit, at various times, 
control strategy SIP revisions and ozone maintenance plans for ozone 
nonattainment areas and for areas seeking redesignation to attainment 
of the ozone standard. These emission control strategy SIP revisions 
(e.g., reasonable further progress SIP and attainment demonstration SIP 
revisions) and ozone maintenance plans create MVEBs based on onroad 
mobile source emissions for criteria pollutants and/or their precursors 
to address pollution from cars and trucks. The MVEBs are the portions 
of the total allowable emissions that are allocated to highway and 
transit vehicle use that, together with emissions from other sources in 
the area, will provide for attainment or maintenance.
    Under 40 CFR Part 93, a MVEB for an area seeking a redesignation to 
attainment is established for the last year of the maintenance plan. 
The MVEB serves as a ceiling on emissions from an area's planned 
transportation system. The MVEB concept is further explained in the 
preamble to the November 24, 1993, transportation conformity rule (58 
FR 62188). The preamble also describes how to establish the MVEB in the 
SIP and how to revise the MVEB if needed.
    Under section 176(c) of the CAA, new transportation projects, such 
as the construction of new highways, must ``conform'' to (i.e., be 
consistent with) the part of the SIP that addresses emissions from cars 
and trucks. Conformity to the SIP means that transportation activities 
will not cause new air quality violations, worsen existing air quality 
violations, or delay timely attainment of the NAAQS. If a 
transportation plan does not conform, most new transportation projects 
that would expand the capacity of roadways cannot go forward. 
Regulations at 40 CFR part 93 set forth EPA policy, criteria, and 
procedures for demonstrating and assuring conformity of such 
transportation activities to a SIP.
    When reviewing SIP revisions containing MVEBs, including attainment 
strategies, rate-of-progress plans, and maintenance plans, EPA must 
affirmatively find that the MVEBs are ``adequate'' for use in 
determining transportation conformity. Once EPA affirmatively finds the 
submitted MVEBs to be adequate for transportation conformity purposes, 
the MVEBs are used by State and Federal agencies in determining whether 
proposed transportation projects conform to the SIP as required by 
section 176(c) of the CAA. EPA's substantive criteria for determining 
the adequacy of MVEBs are set out in 40 CFR 93.118(e)(4).
    EPA's process for determining adequacy of a MVEB consists of three 
basic steps: (1) Providing public notification of a SIP submission; (2) 
providing the public the opportunity to comment on the MVEB during a 
public comment period; and, (3) EPA's finding of adequacy. The process 
of determining the adequacy of submitted SIP MVEBs was initially 
outlined in EPA's May 14, 1999, guidance, ``Conformity Guidance on 
Implementation of March 2, 1999, Conformity Court Decision.'' This 
guidance was codified in the Transportation Conformity Rule Amendments 
for the ``New 8-Hour Ozone and PM2.5 National Ambient Air Quality 
Standards and Miscellaneous Revisions for Existing Areas; 
Transportation Conformity Rule Amendments--Response to Court Decision 
and Additional Rule Change,'' published on July 1, 2004 (69 FR 40004). 
EPA follows this guidance and rulemaking in making its adequacy 
determinations.
    The Columbus area's maintenance plan contains new VOC and 
NOX MVEBs for the years 2009 and 2018. The availability of 
the SIP submission with these 2009 and 2018 MVEBs was announced for 
public comment on EPA's Adequacy Web page on March 5, 2007, at: https://
www.epa.gov/otaq/stateresources/transconf/currsips.htm. The EPA public 
comment period on adequacy of the MVEBs closed on April 6, 2007. No 
requests for the submittal or adverse comments on the submittal were 
received during the adequacy comment period. In a letter dated April 6, 
2007 EPA informed Ohio that we had found the MVEBs to be adequate for 
use in transportation conformity analyses.
    EPA, through this rulemaking, is proposing to approve the MVEBs for 
use in determining transportation conformity in the Columbus area 
because the EPA has determined that the area can maintain attainment of 
the 8-hour ozone NAAQS for the relevant maintenance period with mobile 
source emissions at the levels of the MVEBs.

        Motor Vehicle Emissions Budgets for the Columbus, OH Area
------------------------------------------------------------------------
                                                VOC  (tons/  NOX  (tons/
                     Year                           day)         day)
------------------------------------------------------------------------
2009..........................................        72.16       125.43
2018..........................................        41.50        56.30
------------------------------------------------------------------------

2. What Is a Safety Margin?
    A ``safety margin'' is the difference between the attainment level 
of emissions (from all sources) and the projected level of emissions 
(from all sources) in the maintenance plan. As part of its maintenance 
plan, the State elected to include a ``safety margin'' for the area. 
The attainment level of emissions is the level of emissions during one 
of the years in which the area met the NAAQS. Ohio used 2004 as the 
attainment level of emissions for the area. In the maintenance plan, 
Ohio projected emission levels for 2018. The emissions from point, 
area, non-road, and mobile sources in 2004 equaled 183.84 tons/day of 
VOC and 207.10 tons/day of NOX. Ohio projected VOC emissions 
for the year 2018 to be 127.38 tons/day of VOC and 87.75 tons/day of 
NOX. The safety margin is calculated to be the difference 
between these amounts or, in this case, 56.46 tons/day of VOC and 
119.35 tons/day of NOX for 2018. The safety margin, or a 
portion thereof, can be allocated to any o