Document ID: EPA-R05-OAR-2006-0956-0002
Agency: epa
Document Type: Proposed Rule
Title: Proposed Approval of the Dayton-Springfield Ohio 8-hour Ozone Redesignation and Maintenance Plan
Posted Date: 2007-06-20T04:00Z

[Federal Register: June 20, 2007 (Volume 72, Number 118)]
[Proposed Rules]               
[Page 33937-33948]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20jn07-37]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R05-OAR-2006-0956; FRL-8328-9]

 
Approval and Promulgation of Implementation Plans and Designation 
of Areas for Air Quality Planning Purposes; Ohio; Redesignation of 
Dayton-Springfield Area to Attainment for Ozone

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to make a determination under the Clean Air 
Act (CAA) that the nonattainment area of Dayton-Springfield, Ohio 
(Clark, Green, Miami, and Montgomery Counties) has attained the 8-hour 
ozone National Ambient Air Quality Standard (NAAQS). This determination 
is based on complete, quality-assured ambient air quality monitoring 
data for the 2004-2006 seasons that demonstrate that the 8-hour ozone 
NAAQS have been attained in the area. EPA is also proposing to approve, 
as a revision to the Ohio State Implementation Plan (SIP), the State's 
plan for maintaining the 8-hour ozone NAAQS through 2018 in the area.
    EPA is proposing to approve a request from the State of Ohio to 
redesignate the Dayton-Springfield area to attainment of the 8-hour 
ozone NAAQS. The Ohio Environmental Protection Agency (OEPA) submitted 
this request on November 6, 2006 and supplemented it on November 29, 
2006, December 4, 2006, December 13, 2006, January 11, 2007, March 9, 
2007, March 27, 2007, and May 31, 2007. EPA is also proposing to 
approve the State's 2005 and 2018 Motor Vehicle Emission Budgets 
(MVEBs) for the Dayton-Springfield area.

DATES: Comments must be received on or before July 20, 2007.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2006-0956, by one of the following methods:
    1. http://www.regulations.gov: Follow the on-line instructions for 

submitting comments.
    2. E-mail: mooney.john@epa.gov.
    3. Fax: (312) 886-5824.
    4. 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.
    5. 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-
2006-0956. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://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 http://www.regulations.gov 

or e-mail. The http://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 
http://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 
http://www.regulations.gov

[[Page 33938]]

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 
http://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 Kathleen D'Agostino, Environmental 
Engineer, at (312) 886-1767 before visiting the Region 5 office.

FOR FURTHER INFORMATION CONTACT: Kathleen D'Agostino, Environmental 
Engineer, Criteria Pollutant Section, Air Programs Branch (AR-18J), 
Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, 
Chicago, Illinois 60604, (312) 886-1767, dagostino.kathleen@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?
    A. What Is the General Background Information?
    B. What Is the Impact of the December 22, 2006 United States 
Court of Appeals Decision Regarding EPA's Phase 1 Implementation 
Rule?
IV. What Are the Criteria for Redesignation?
V. Why Is EPA Proposing To Take These Actions?
VI. What Is the Effect of These Actions?
VII. What Is EPA's Analysis of the Requests?
    A. Attainment Determination and Redesignation
    B. Adequacy of Ohio's MVEBs
VIII. What Actions Is EPA Taking?
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 make a determination that the Dayton-Springfield nonattainment area 
has attained the 8-hour ozone standard and that this area has met the 
requirements for redesignation under section 107(d)(3)(E) of the CAA. 
EPA is thus proposing to approve Ohio's request to change the legal 
designation of the Dayton-Springfield area from nonattainment to 
attainment for the 8-hour ozone NAAQS. EPA is also proposing to approve 
Ohio's maintenance plan SIP revision for Dayton-Springfield (such 
approval being one of the CAA criteria for redesignation to attainment 
status). The maintenance plan is designed to keep the Dayton-
Springfield area in attainment of the ozone NAAQS through 2018. 
Additionally, EPA is proposing to approve the newly-established 2005 
and 2018 MVEBs for the Dayton-Springfield area. The adequacy comment 
period for the MVEBs began on November 14, 2006, with EPA's posting of 
the availability of the submittal on EPA's Adequacy Web site (at http://www.epa.gov/otaq/stateresources/transconf/adequacy.htm
). The adequacy 

comment period for these MVEBs ended on December 14, 2006. EPA did not 
receive any requests for this submittal, or adverse comments on this 
submittal during the adequacy comment period. On April 3, 2007, EPA 
published a Federal Register notice announcing the adequacy of the 2005 
and 2018 MVEBs. Please see the Adequacy section of this rulemaking for 
further explanation on this process. Therefore, we find adequate, and 
are proposing to approve, the State's 2005 and 2018 MVEBs for 
transportation conformity purposes.

III. What Is the Background for These Actions?

A. What Is the General Background Information?

    Ground-level ozone is not emitted directly by sources. Rather, 
emissions of nitrogen oxides (NOX) and volatile organic 
compounds (VOCs) react in the presence of sunlight to form ground-level 
ozone. NOX and VOCs are referred to as precursors of ozone.
    The CAA establishes a process for air quality management through 
the NAAQS. Before promulgation of the current 8-hour standard, the 
ozone NAAQS was based on a 1-hour standard. On November 6, 1991 (56 FR 
56693 and 56813), the Dayton-Springfield area was designated as a 
moderate nonattainment area under the 1-hour ozone NAAQS. The area was 
subsequently redesignated to attainment of the 1-hour standard on May 
5, 1995 (60 FR 22289). At the time EPA revoked the 1-hour ozone NAAQS, 
on June 15, 2005, the Dayton-Springfield area was designated as 
attainment under the 1-hour ozone NAAQS.
    On July 18, 1997, EPA promulgated a revised 8-hour ozone standard 
of 0.08 parts per million (ppm). This new standard is more stringent 
than the previous 1-hour standard. On April 30, 2004 (69 FR 23857), EPA 
published a final rule designating and classifying areas under the 8-
hour ozone NAAQS. These designations and classifications became 
effective June 15, 2004. The CAA required EPA to designate as 
nonattainment any area that was violating the 8-hour ozone NAAQS based 
on the three most recent years of air quality data, 2001-2003.
    The CAA contains two sets of provisions, subpart 1 and subpart 2, 
that address planning and control requirements for nonattainment areas. 
(Both are found in title I, part D, 42 U.S.C. 7501-7509a and 7511-
7511f, respectively.) Subpart 1 contains general requirements for 
nonattainment areas for any pollutant, including ozone, governed by a 
NAAQS. Subpart 2 provides more specific requirements for ozone 
nonattainment areas.
    Under EPA's 8-hour ozone implementation rule, (69 FR 23951 (April 
30, 2004)), an area was classified under subpart 2 based on its 8-hour 
ozone design value (i.e., the 3-year average annual fourth-highest 
daily maximum 8-hour average ozone concentration), if it had a 1-hour 
design value at the time of designation at or above 0.121 ppm (the 
lowest 1-hour design value in Table 1 of subpart 2) (69 FR 23954). All 
other areas are covered under subpart 1, based upon their 8-

[[Page 33939]]

hour design values (69 FR 23958). The Dayton-Springfield area was 
designated as a subpart 1, 8-hour ozone nonattainment area by EPA on 
April 30, 2004, (69 FR 23857, 23927) based on air quality monitoring 
data from 2001-2003 (69 FR 23860).
    40 CFR 50.10 and 40 CFR Part 50, Appendix I provide that the 8-hour 
ozone standard is attained 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, when rounded. The data completeness 
requirement is met when the average percent of days with valid ambient 
monitoring data is greater than 90%, and no single year has less than 
75% data completeness. See 40 CFR Part 50, Appendix I, 2.3(d).
    On November 6, 2006, Ohio requested that EPA redesignate the 
Dayton-Springfield area to attainment for the 8-hour ozone standard. 
Ohio supplemented its submittal on November 29, 2006, December 4, 2006, 
December 13, 2006, January 11, 2007, March 9, 2007, March 27, 2007, and 
May 31, 2007. The redesignation request included three years of 
complete, quality-assured data for the period of 2004 through 2006, 
indicating the 8-hour NAAQS for ozone had been attained for the Dayton-
Springfield 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).

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 Circuit vacated EPA's Phase 1 Implementation Rule for the 8-
hour Ozone Standard. (69 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 
Dayton-Springfield 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 
Dayton-Springfield 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

[[Page 33940]]

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 
(December 7, 1995) (Tampa, FL redesignation).
    Federal transportation conformity regulations apply in all States 
prior to approval of transportation conformity SIPs. The Dayton-
Springfield, 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, the Dayton-Springfield 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.
    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?

    The CAA provides the requirements for redesignating a nonattainment 
area to attainment. Specifically, section 107(d)(3)(E) allows for 
redesignation 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 the following documents:
    ``Ozone and Carbon Monoxide Design Value Calculations,'' Memorandum 
from William G. Laxton, Director Technical Support Division, June 18, 
1990;
    ``Maintenance Plans for Redesignation of Ozone and Carbon Monoxide 
Nonattainment Areas,'' Memorandum from G.T. Helms, Chief, Ozone/Carbon 
Monoxide Programs Branch, April 30, 1992;
    ``Contingency Measures for Ozone and Carbon Monoxide (CO) 
Redesignations,'' Memorandum from G.T. Helms, Chief, Ozone/Carbon 
Monoxide Programs Branch, June 1, 1992;
    ``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' Memorandum from John Calcagni, Director, Air Quality 
Management Division, September 4, 1992;
    ``State Implementation Plan (SIP) Actions Submitted in Response to 
Clean Air Act (ACT) Deadlines,'' Memorandum from John Calcagni, 
Director, Air Quality Management Division, October 28, 1992;
    ``Technical Support Documents (TSD's) for Redesignation Ozone and 
Carbon Monoxide (CO) Nonattainment Areas,'' Memorandum from G.T. Helms, 
Chief, Ozone/Carbon Monoxide Programs Branch, August 17, 1993;
    ``State Implementation Plan (SIP) Requirements for Areas Submitting 
Requests for Redesignation to Attainment of the Ozone and Carbon 
Monoxide (CO) National Ambient Air Quality Standards (NAAQS) On or 
After November 15, 1992,'' Memorandum from Michael H. Shapiro, Acting 
Assistant Administrator for Air and Radiation, September 17, 1993;
    ``Use of Actual Emissions in Maintenance Demonstrations for Ozone 
and CO Nonattainment Areas,'' Memorandum from D. Kent Berry, Acting 
Director, Air Quality Management Division, to Air Division Directors, 
Regions 1-10, dated November 30, 1993.
    ``Part D New Source Review (part D NSR) Requirements for Areas 
Requesting Redesignation to Attainment,'' Memorandum from Mary D. 
Nichols, Assistant Administrator for Air and Radiation, October 14, 
1994; and
    ``Reasonable Further Progress, Attainment Demonstration, and 
Related Requirements for Ozone Nonattainment Areas Meeting the Ozone 
National Ambient Air Quality Standard,'' Memorandum from John S. Seitz, 
Director, Office of Air Quality Planning and Standards, May 10, 1995.''

V. Why Is EPA Proposing To Take These Actions?

    On November 6, 2006, Ohio requested redesignation of the Dayton-
Springfield area to attainment for the 8-hour ozone standard. Ohio 
supplemented its submittal on November 29, 2006, December 4, 2006, 
December 13, 2006, January 5, 2007, January 11, 2007, March 9, 2007, 
March 27, 2007, and May 31, 2007. 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 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 plan includes 
contingency measures to remedy future violations of the 8-hour NAAQS. 
It also establishes MVEBs of 29.19 and 14.73 tons per day (tpd) VOC and 
63.88 and 21.42 tpd NOX for the years 2005 and 2018, 
respectively.

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

A. Attainment Determination and Redesignation

    EPA is proposing to make a determination that the Dayton-
Springfield area has attained the 8-hour ozone standard and that the 
area has met all other applicable section 107(d)(3)(E) redesignation 
criteria. The basis for EPA's determination is as follows:
1. The Area Has Attained the 8-Hour Ozone NAAQS. (Section 
107(d)(3)(E)(i))
    EPA is proposing to make a determination that the Dayton-
Springfield area has attained the 8-hour ozone NAAQS. For ozone, an 
area may be considered to be attaining the 8-hour

[[Page 33941]]

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. To attain this standard, the 3-year average of the fourth-highest 
daily maximum 8-hour average ozone concentrations measured at each 
monitor within an area over each year must not exceed 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.
    OEPA submitted ozone monitoring data for the 2004 to 2006 ozone 
seasons. The OEPA quality-assured the ambient monitoring 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. Monitoring 
data is presented in Table 1 below. Data completeness information is 
presented in Table 2 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
                                                               2004  4th    2005  4th    2006  4th     average
             County                         Monitor           high  (ppm)  high  (ppm)  high  (ppm)    4th high
                                                                                                        (ppm)
----------------------------------------------------------------------------------------------------------------
Clark...........................  Springfield, 39-023-001...        0.079        0.086        0.076        0.080
                                  Mud Run, 39-023-0003......        0.073        0.081        0.074        0.076
Greene..........................  Xenia, 39-057-0006........        0.075        0.083        0.079        0.079
Miami...........................  Miami, 39-109-0005........        0.075        0.079        0.073        0.076
Montgomery......................  Webster, 39-113-0033......        0.067        0.082        0.071        0.073
----------------------------------------------------------------------------------------------------------------

                                   Table 2.--Data Completeness in Percent (%)
----------------------------------------------------------------------------------------------------------------
                                                                                                      2004-2006
             County                         Monitor             2004 (%)     2005 (%)     2006 (%)   average (%)
----------------------------------------------------------------------------------------------------------------
Clark...........................  Springfield, 39-023-001...          100           99          100          100
                                  Mud Run, 39-023-0003......           99           99          100           99
Greene..........................  Xenia, 39-057-0006........          100          100          100          100
Miami...........................  Miami, 39-109-0005........           99          100           99           99
Montgomery......................  Webster, 39-113-0033......           98          100          100           99
----------------------------------------------------------------------------------------------------------------

    In addition, as discussed below with respect to the maintenance 
plans, OEPA has committed to continue operating the ozone monitors 
listed above. OEPA has also committed to consult with EPA prior to 
making changes to the existing monitoring network, should changes 
become necessary in the future. OEPA will continue to quality assure 
and report monitoring data in accordance with 40 CFR part 58 and all 
other federal requirements. In summary, EPA believes that the data 
submitted by Ohio provide an adequate demonstration that the Dayton-
Springfield 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 Dayton-Springfield 
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 Ohio 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. The Dayton-Springfield Area 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

[[Page 33942]]

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, 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,\1\ 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 
classification 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 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).
---------------------------------------------------------------------------

    \1\ On October 27, 1998 (63 FR 57356), EPA issued a 
NOX SIP call requiring the District of Columbia and 22 
states, including Ohio, to reduce emissions of NOX in 
order to reduce the transport of ozone and ozone precursors. In 
compliance with EPA's NOX SIP call, OEPA has developed 
rules governing the control of NOX emissions from 
Electric Generating Units (EGUs), major non-EGU industrial boilers, 
and major cement kilns. EPA approved Ohio's rules as fulfilling 
Phase I of the NOX SIP Call on June 27, 2005 (70 FR 
36845).
---------------------------------------------------------------------------

    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 OEPA's submission of the 
redesignation request for the Dayton-Springfield 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. The Dayton-Springfield area was 
classified as a subpart 1 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 Dayton-Springfield area are contained in 
sections 172(c)(1)-(9). A thorough discussion of the requirements 
contained in section 172 can be found in the General Preamble for 
Implementation of Title I (57 FR 13498, April 16, 1992).
    No 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 areas for purposes of 
redesignation. Since the State of Ohio has submitted a complete ozone 
redesignation request for the Dayton-Springfield area prior to the 
deadline for any submissions required for purposes of redesignation, we 
have determined that these requirements do not apply to the Dayton-
Springfield area for purposes of redesignation.
    Furthermore, EPA has determined that, since PSD requirements will 
apply after redesignation, areas being redesignated need not comply 
with the requirement that a NSR program be approved prior to 
redesignation, provided that the area demonstrates maintenance of the 
NAAQS without part D NSR. A more detailed rationale for this view is 
described in a memorandum from Mary Nichols, Assistant Administrator 
for Air and Radiation, dated October 14, 1994, entitled, ``Part D New 
Source Review Requirements for Areas Requesting Redesignation to 
Attainment.'' Ohio has demonstrated that the area to be redesignated 
will be able to maintain the standard without part D NSR in effect; 
therefore, EPA concludes that the State need not have a fully approved 
part D NSR program prior to approval of the redesignation request. The 
State's PSD program will become effective in the Dayton-Springfield 
area upon redesignation to attainment. See rulemakings for Detroit, 
Michigan (60 FR 12467-12468, March 7, 1995); Cleveland-Akron-Lorain, 
Ohio (61 FR 20458, 20469-20470, May 7, 1996); Louisville, Kentucky (66 
FR 53665, October 23, 2001); and Grand Rapids, Michigan (61 FR 31834-
31837, June 21, 1996).
    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

[[Page 33943]]

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 believes that it is reasonable to interpret the conformity SIP 
requirements as not applying for purposes of evaluating the 
redesignation request under section 107(d) for two reasons. First, the 
requirement to submit SIP revisions to comply with the conformity 
provisions of the CAA continues to apply to areas after redesignation 
to attainment since such areas would be subject to a section 175A 
maintenance plan. Second, EPA's federal conformity rules require the 
performance of conformity analyses in the absence of federally-approved 
state rules. Therefore, because areas are subject to the conformity 
requirements regardless of whether they are redesignated to attainment 
and, because they must implement conformity under federal rules if 
state rules are not yet approved, EPA believes it is reasonable to view 
these requirements as not applying for purposes of evaluating a 
redesignation request. See Wall v. EPA, 265 F.3d 426 (6th Cir. 2001), 
upholding this interpretation. See also 60 FR 62748, 62749-62750 (Dec. 
7, 1995) (Tampa, Florida).
    EPA approved Ohio's general and transportation conformity SIPs on 
March 11, 1996 (61 FR 9646) and May 30, 2000 (65 FR 34395), 
respectively. Ohio has submitted on-highway motor vehicle budgets for 
the Dayton-Springfield area of 29.19 and 14.73 tpd VOC and 63.88 and 
21.42 tpd NOX for the years 2005 and 2018, respectively. The 
area must use the MVEBs from the maintenance plan in any conformity 
determination that is effective on or after the effective date of the 
maintenance plan approval. Thus, the Dayton-Springfield area has 
satisfied all applicable requirements under section 110 and part D of 
the CAA.
b. The Dayton-Springfield Area Has a Fully Approved Applicable SIP 
Under Section 110(k) of the CAA
    EPA has fully approved the Ohio SIP for the Dayton-Springfield area 
under section 110(k) of the CAA for all requirements applicable for 
purposes of redesignation. EPA may rely on prior SIP approvals in 
approving a redesignation request (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)) plus any additional measures it may approve 
in conjunction with a redesignation action. See 68 FR 25413, 25426 (May 
12, 2003). 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 Dayton-Springfield area 
under the 1-hour ozone standard. No Dayton-Springfield 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 Resulting From Implementation of the SIP and 
Applicable Federal Air Pollution Control Regulations and Other 
Permanent and Enforceable Reductions. (Section 107(d)(3)(E)(iii))
    EPA finds that Ohio has demonstrated that the observed air quality 
improvement in the Dayton-Springfield 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 2005, one of the years the Dayton-
Springfield 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 and 
upwind areas have implemented in recent years. The Dayton-Springfield 
is impacted by the transport of ozone and ozone precursors from upwind 
areas. Therefore, local controls as well as controls implemented in 
upwind areas are relevant to the improvement in air quality in the 
Dayton-Springfield area.
a. Permanent and Enforceable Controls Implemented
    The following is a discussion of permanent and enforceable measures 
that have been implemented in the areas:
    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. From 2004 on, NOX 
emissions from EGUs and large industrial boilers have been capped at a 
level well below pre-2002 levels. OEPA 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)) 
and CAIR.
    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: The National Low 
Emission Vehicle (NLEV) program, 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.
    Control Measures in Upwind Areas. On October 27, 1998 (63 FR 
57356), EPA issued a NOX SIP call requiring the District of 
Columbia and 22 states, including Ohio, to reduce emissions of 
NOX. The reduction in NOX emissions has resulted 
in lower concentrations of transported ozone entering the Dayton-
Springfield area. Emission reductions resulting from regulations 
developed in response to the NOX SIP call are permanent and 
enforceable.
b. Emission Reductions
    Ohio is using 2002 for the nonattainment inventory and 2005, one of 
the years used to demonstrate monitored attainment of the NAAQS, for 
the attainment inventory. OEPA developed a 2002 base year inventory 
which they provided to the Lake Michigan Air Directors Consortium 
(LADCO). The base year inventory was processed by LADCO to develop 
summer day emissions for use in regional air quality analyses and 
attainment demonstration modeling. Area source emissions data were 
taken from the Ohio 2002 periodic inventory submitted to EPA. Onroad 
mobile source emissions were calculated using MOBILE6.2. Point source 
emissions data was compiled from Ohio's STARShip annual emissions 
inventory database and EPA's 2002 Air Markets acid rain database. 
Nonroad mobile emissions were generated using EPA's National Mobile 
Inventory Model (NMIM), with the following exceptions. Recreational 
motorboat populations and spatial surrogates were updated and emissions 
estimates were developed for aircraft, commercial marine vessels, and 
railroads, three nonroad categories not included in NMIM. For 2005, 
OEPA

[[Page 33944]]

estimated point, area, and nonroad mobile source emissions by 
interpolating between the 2002 inventory and the 2009 inventory 
described below. Onroad emissions were generated using MOBILE6.2.
    Based on the inventories described above, Ohio's submittal 
documents changes in VOC and NOX emissions from 2002 to 2005 
for the Dayton-Springfield area. Emissions data are shown in Tables 3 
through 5 below.

                            Table 3.--Dayton-Springfield Area: Total VOC and NOX Emissions for Nonattainment Year 2002 (tpd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Clark                Greene                 Miami              Montgomery               Total
                                           -------------------------------------------------------------------------------------------------------------
                                               VOC        NOX        VOC        NOX        VOC        NOX        VOC        NOX        VOC        NOX
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point.....................................       0.55       0.11       0.05       9.30       0.29       0.05       2.61      29.32       3.50      38.78
Area......................................      10.40       0.70       5.98       0.67       6.34       0.53      22.35       2.43      45.07       4.33
Nonroad...................................       1.94       3.56       1.79       3.70       1.74       3.49       8.62      12.17      14.09      22.92
Onroad....................................       6.62      14.54       6.22      12.26       4.95       9.88      20.80      41.77      38.59      78.45
                                           -------------------------------------------------------------------------------------------------------------
    Total.................................      19.51      18.91      14.04      25.93      13.32      13.95      54.38      85.69     101.25     144.48
--------------------------------------------------------------------------------------------------------------------------------------------------------

                              Table 4.--Dayton-Springfield Area: Total VOC and NOX Emissions for Attainment Year 2005 (tpd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Clark                Greene                 Miami              Montgomery               Total
                                           -------------------------------------------------------------------------------------------------------------
                                               VOC        NOX        VOC        NOX        VOC        NOX        VOC        NOX        VOC        NOX
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point.....................................       0.50       0.11       0.05       8.75       0.30       0.05       2.60      27.69       3.45      36.60
Area......................................      11.02       0.75       6.08       0.72       6.46       0.56      22.67       2.62      46.23       4.65
Nonroad...................................       1.68       3.16       1.60       3.37       1.55       3.07       7.33      10.64      12.16      20.24
Onroad....................................       4.98      11.82       4.74      10.04       3.81       8.17      15.66      33.85      29.19      63.88
                                           -------------------------------------------------------------------------------------------------------------
    Total.................................      18.18      15.84      12.47      22.88      12.12      11.85      48.26      74.80      91.03     125.37
--------------------------------------------------------------------------------------------------------------------------------------------------------

                               Table 5.--Dayton-Springfield Area: Comparison of 2002 and 2005 VOC and NOX Emissions (tpd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                VOC                                             NOX
                                                         -----------------------------------------------------------------------------------------------
                         Sector                                                             Net change                                      Net change
                                                               2002            2005         (2002-2005)        2002            2005         (2002-2005)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point...................................................            3.50            3.45           -0.05           38.78           36.60           -2.18
Area....................................................           45.07           46.23            1.16            4.33            4.65            0.32
Nonroad.................................................           14.09           12.16           -1.93           22.92           20.24           -2.68
Onroad..................................................           38.59           29.19            -9.4           78.45           63.88          -14.57
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................          101.25           91.03          -10.22          144.48          125.37          -19.11
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Table 5 shows that the Dayton-Springfield area reduced VOC 
emissions by 10.22 tpd and NOX emissions by 19.11 tpd 
between 2000 and 2005. 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 Areas Have Fully Approved Maintenance Plans Pursuant to Section 
175a of the CAA. (Section 107(d)(3)(E)(iv))
    In conjunction with its requests to redesignate the Dayton-
Springfield nonattainment area to attainment status, Ohio submitted a 
SIP revision to provide for the maintenance of the 8-hour ozone NAAQS 
in the 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
    The OEPA developed an emissions inventory for 2005, one of the 
years Ohio used to demonstrate monitored attainment of the 8-hour 
NAAQS, as described above. The attainment level of emissions is 
summarized in Table 4, above.

[[Page 33945]]

c. Demonstration of Maintenance
    Ohio submitted with the redesignation request a revision to the 8-
hour ozone SIP to include a maintenance plan for the Dayton-Springfield 
area, in compliance with section 175A of the CAA. This demonstration 
shows maintenance of the 8-hour ozone standard through 2018 by assuring 
that current and future emissions of VOC and NOX for the 
Dayton-Springfield 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 primarily using inventories developed by LADCO for the 
years 2009 and 2018. Point and area source emissions were projected 
from the 2002 base year to 2009 and 2018 using growth factors. LADCO 
point source estimates have been supplemented with point source 
emissions projections based upon data compiled from Ohio's STARShip 
annual emissions inventory database and statewide EGU NOX 
budgets from the Ohio NOX rule. Nonroad mobile emissions 
were generated for 2009 and 2018 using NMIM, with the following 
exceptions. Recreational motorboat populations and spatial surrogates 
were updated and emissions estimates were developed for aircraft, 
commercial marine vessels, and railroads, three nonroad categories not 
included in NMIM. The Ohio Department of Transportation prepared onroad 
mobile source emissions estimates using MOBILE6.2. Modeling for 2009 
and 2018 includes implementation of the 7.8 low Reid Vapor Pressure 
fuels program for the area. It should be noted that because Ohio is in 
the process of seeking approval of the removal of the vehicle 
inspection and maintenance (I/M) program from the Dayton-Springfield 
SIP, MOBILE6.2 modeling was performed assuming no credit for I/M 
related emissions reductions in 2009 and 2018. This results in 
conservatively estimating onroad emissions to be higher in 2009 and 
2018 than would be the case if the I/M program were to continue to 
operate. While the issue of I/M program discontinuation will be 
addressed in a separate action, it should be noted that Ohio's 
maintenance plan demonstrates that the area can maintain the standard 
through 2018 without operation of the I/M program. Emissions estimates 
are presented in Table 6 below.

                                 Table 6.--Dayton-Springfield Area: Comparison of 2005-2018 VOC and NOX Emissions (tpd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          VOC                                                 NOX
                                                 -------------------------------------------------------------------------------------------------------
                     Sector                                                               Net change                                          Net change
                                                      2005         2009         2018      2005-2018       2005         2009         2018      2005-2018
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point...........................................         3.45         3.47         3.72         0.27        36.60        36.24        37.94         1.34
Area............................................        46.23        47.76        52.75         6.52         4.65         5.09         5.45         0.80
Nonroad.........................................        12.16         9.62         7.91        -4.25        20.24        16.68         9.84       -10.40
Onroad..........................................        29.19        20.50        11.66       -17.53        63.88        46.78        18.50       -45.38
                                                 -------------------------------------------------------------------------------------------------------
    Total.......................................        91.03        81.35        76.04       -14.99       125.37       104.79        71.73       -53.64
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The emission projections show that OEPA does not expect emissions 
in the Dayton-Springfield area to exceed the level of the 2005 
attainment year inventory during the maintenance period. In the Dayton-
Springfield area, OEPA projects that VOC and NOX emissions 
will decrease by 14.99 tpd and 53.64 tpd, 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. The Dayton-Springfield area 
attained the 8-hour ozone NAAQS during the 2004-2006 time period. Ohio 
used 2005 as the attainment level of emissions for the area. In the 
maintenance plan, OEPA projected emission levels for 2018. For Dayton-
Springfield, the emissions from point, area, nonroad, and mobile 
sources in 2005 equaled 91.03 tpd of VOC. OEPA projected VOC emissions 
for the year 2018 to be 76.04 tpd of VOC. The SIP submission 
demonstrates that the Dayton-Springfield area will continue to maintain 
the standard with emissions at this level. The safety margin for VOC is 
calculated to be the difference between these amounts or, in this case, 
14.99 tpd of VOC for 2018. By this same method, 53.64 tpd (i.e., 125.37 
tpd less 71.73 tpd) is the safety margin for 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.
d. Monitoring Network
    Ohio currently operates two ozone monitors in Clark County, and one 
ozone monitor each in Greene, Miami, and Montgomery Counties. OEPA has 
committed to continue operating the ozone monitors located in these 
counties. OEPA has also committed to consult with EPA prior to making 
changes to the existing monitoring network, should changes become 
necessary in the future. OEPA will continue to quality assure and 
report monitoring data in accordance with 40 CFR part 58 and all other 
federal requirements.
e. Verification of Continued Attainment
    Continued attainment of the ozone NAAQS in the Dayton-Springfield 
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 Dayton-Springfield area consists of plans to continue ambient 
ozone monitoring in accordance with the requirements of 40 CFR part 58.
f. Contingency Plan
    The contingency plan provisions are designed to promptly correct or 
prevent a violation of the NAAQS that might occur after redesignation 
of an area to attainment. 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 occurs after redesignation. The maintenance plan should 
identify the contingency measures to be adopted, a schedule and 
procedure for adoption and

[[Page 33946]]

implementation of the 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 contained in the SIP before 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 for the Dayton-Springfield area to address possible 
future ozone air quality problems. The contingency plan adopted by Ohio 
has two levels of response, depending on whether a violation of the 8-
hour ozone standard is only threatened (Warning Level Response) or has 
occurred (Action Level Response).
    A Warning Level Response will occur when an annual (1-year) fourth-
high monitored daily peak 8-hour ozone concentration of 0.88 ppm is 
monitored within the maintenance area. A Warning Level Response will 
consist of a study to determine whether the high ozone value indicates 
a trend toward higher ozone concentrations and whether emissions appear 
to be increasing. The study will evaluate whether the trend, if any, is 
likely to continue. If so, control measures necessary to reverse the 
trend will be selected by the State for evaluation and possible 
adoption. Implementation of necessary controls in response to a Warning 
Level Response triggering will occur as expeditiously as possible, but 
in no event later than 12 months from the conclusion of the most recent 
ozone season (September 30).
    An Action Level Response will be triggered whenever a two-year 
average fourth-high monitored value of 0.85 ppm or greater is monitored 
within the area, or a violation of the NAAQS (three-year average 
fourth-high value of 0.85 ppm or greater) is monitored within the area. 
When an Action Level Response is triggered, OEPA, in conjunction with 
the metropolitan planning organization or regional council of 
governments, will determine what control measures are needed to assure 
future attainment of the NAAQS. 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.
    The State will select contingency measures for consideration from a 
comprehensive list of measures deemed appropriate and effective at the 
time the selection is made. In its maintenance plan, OEPA included the 
following list of possible contingency measures:
    i. Lower Reid vapor pressure gasoline program;
    ii. Tighten RACT on existing sources covered by U.S. EPA Control 
Technique Guidelines issued in response to the 1990 CAA;
    iii. Apply RACT to smaller existing sources;
    iv. Alternative fuel and diesel retrofit programs for fleet vehicle 
operations;
    v. Controls on consumer products consistent with those adopted 
elsewhere in the United States;
    vi. Require VOC or NOX emission offsets for new and 
modified major sources;
    vii. Require VOC or NOX emission offsets for new and 
modified minor sources;
    viii. Increase the ratio of emission offsets required for new 
sources; and
    ix. Require VOC or NOX controls on new minor sources 
(less than 100 tons).
    It should be noted that a lower Reid vapor pressure gasoline 
program would only be creditable as a contingency measure to the extent 
that it goes beyond the program currently approved and included in the 
maintenance plan emissions estimates.
    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 of the Dayton-Springfield area to cover an additional 10-
year period beyond the initial 10-year maintenance period. As required 
by section 175(A) of the CAA, Ohio has committed to maintaining the 
existing controls after redesignation unless the State demonstrates 
that the standard can be maintained without one or more controls. Ohio 
commits that any changes to its rules or emission limits applicable to 
VOC and/or NOX sources, as required for maintenance of the 
ozone standard in the Dayton-Springfield area will be submitted to EPA 
for approval as a SIP revision.
    EPA has concluded 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. The maintenance plan SIP 
revision submitted by Ohio for the Dayton-Springfield area meets the 
requirements of section 175A of the CAA.

B. Adequacy of Ohio's MVEBs

1. How Are MVEBs Developed and What Are the MVEBs for the Dayton-
Springfield 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 redesignations 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

[[Page 33947]]

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 Dayton-Springfield area's maintenance plan contains new VOC and 
NOX MVEBs for the years 2005 and 2018. The availability of 
the SIP submission with these 2005 and 2018 MVEBs was announced for 
public comment on EPA's Adequacy Web page on November 14, 2006 at: 
http://www.epa.gov/otaq/stateresources/transconf/currsips.htm. The EPA 

public comment period on adequacy of the 2005 and 2018 MVEBs for the 
Dayton-Springfield area closed on December 14, 2006. No requests for 
this submittal or adverse comments on the submittal were received 
during the adequacy comment period. In a letter dated February 9, 2007, 
EPA informed OEPA that we had found the 2005 and 2018 MVEBs to be 
adequate for use in transportation conformity analyses. EPA published a 
Federal Register notice announcing the adequacy of the 2005 and 2018 
MVEBs on April 3, 2007 (72 FR 15879).
    EPA, through this rulemaking, is proposing to approve the MVEBs for 
use to determine transportation conformity in the Dayton-Springfield 
area because 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. OEPA has determined 
the 2005 MVEBs for the Dayton-Springfield area to be 29.19 tpd for VOC 
and 63.88 tpd for NOX. OEPA has determined the 2018 MVEBs 
for the area to be 14.73 tpd for VOC and 21.42 tpd for NOX. 
These MVEBs exceed the onroad mobile source VOC and NOX 
emissions projected by MDEQ for 2018, as summarized in Table 6 above 
(``onroad'' source sector). OEPA decided to include safety margins 
(described further below) of 3.07 tpd for VOC and 2.92 tpd for 
NOX in the MVEBs to provide for mobile source growth. Ohio 
has demonstrated that the Dayton-Springfield area can maintain the 8-
hour ozone NAAQS with mobile source emissions of 14.73 tpd of VOC and 
21.42 tpd of NOX in 2018, including the allocated safety 
margins, since emissions will still remain under attainment year 
emission levels.
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 noted in Table 6, the 
Dayton-Springfield area VOC and NOX emissions are projected 
to have safety margins of 14.99 tpd for VOC and 53.64 tpd for 
NOX in 2018 (the difference between the attainment year, 
2005, emissions and the projected 2018 emissions for all sources in the 
Dayton-Springfield area). Even if emissions reached the full level of 
the safety margin, the area would still demonstrate maintenance since 
emission levels would equal those in the attainment year.
    The MVEBs requested by OEPA contain safety margins for mobile 
sources smaller than the allowable safety margins reflected in the 
total emissions for Dayton-Springfield area. The State is not 
requesting allocation of the entire available safety margins reflected 
in the demonstration of maintenance. Therefore, even though the State 
is requesting MVEBs that exceed the projected onroad mobile source 
emissions for 2018 contained in the demonstration of maintenance, the 
increase in onroad mobile source emissions that can be considered for 
transportation conformity purposes is well within the safety margins of 
the ozone maintenance demonstration. Further, once allocated to mobile 
sources, these safety margins will not be available for use by other 
sources.

VIII. What Actions Is EPA Taking?

    EPA is proposing to make a determination that the Dayton-
Springfield area has attained the 8-hour ozone NAAQS. EPA is also 
proposing to approve the maintenance plan SIP revision for the Dayton-
Springfield area. EPA's proposed approval of the maintenance plan is 
based on Ohio's demonstration that the plan meets the requirements of 
section 175A of the CAA, as described more fully above. After 
evaluating Ohio's redesignation request, EPA has determined that it 
meets the redesignation criteria set forth in section 107(d)(3)(E) of 
the CAA. Therefore, EPA is proposing to approve the redesignation of 
the Dayton-Springfield area from nonattainment to attainment for the 8-
hour ozone NAAQS. The final approval of this redesignation request 
would change the official designation for the Dayton-Springfield area 
from nonattainment to attainment for the 8-hour ozone standard. 
Finally, EPA is proposing to approve the 2005 and 2018 MVEBs submitted 
by Ohio in conjunction with the redesignation request.

IX. Statutory and Executive Order Reviews

Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, September 30, 1993), this 
action is not a ``significant regulatory action'' and, therefore, is 
not subject to review by the Office of Management and Budget.

Paperwork Reduction Act

    This proposed rule does not impose an information collection burden 
under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 
3501 et seq.).

Regulatory Flexibility Act

    This proposed action merely proposes to approve state law as 
meeting federal requirements and imposes no additional requirements 
beyond those imposed by state law. Redesignation of an area to 
attainment under section 107(d)(3)(E) of the CAA does not impose any 
new requirements on small entities. Redesignation is an action that 
affects the status of a geographical area and does not impose any new 
regulatory requirements on sources. Accordingly, the Administrator 
certifies that this rule will not have a significant economic impact on 
a substantial number of small entities under the Regulatory Flexibility 
Act (5 U.S.C. 601 et seq.).

Unfunded Mandates Reform Act

    Because this rule proposes to approve pre-existing requirements 
under state law, and does not impose any additional enforceable duty 
beyond that required by state law, it does not contain any unfunded 
mandate or significantly or uniquely affect small governments, as 
described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4).

[[Page 33948]]

Executive Order 13132: Federalism

    This action also does not have Federalism implications because it 
does 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 (64 FR 43255, August 
10, 1999). Redesignation is an action that merely affects the status of 
a geographical area, does not impose any new requirements on sources, 
or allows a state to avoid adopting or implementing other requirements, 
and does not alter the relationship or the distribution of power and 
responsibilities established in the CAA.

Executive Order 13175: Consultation and Coordination With Indian Tribal 
Governments

    This proposed rule also does not have tribal implications because 
it will not have a substantial direct effect on one or more Indian 
tribes, on the relationship between the Federal Government and Indian 
tribes, or on the distribution of power and responsibilities between 
the Federal Government and Indian tribes, as specified by Executive 
Order 13175 (65 FR 67249, November 9, 2000).

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

    This proposed rule also is not subject to Executive Order 13045 
``Protection of Children from Environmental Health Risks and Safety 
Risks'' (62 FR 19885, April 23, 1997), because it is not economically 
significant.

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

    Because it is not a ``significant regulatory action'' under 
Executive Order 12866 or a ``significant energy action,'' this action 
is also not subject to Executive Order 13211, ``Actions Concerning 
Regulations That Significantly Affect Energy Supply, Distribution, or 
Use'' (66 FR 28355, May 22, 2001).

National Technology Transfer Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTA), 15 U.S.C. 272, requires federal agencies to use 
technical standards that are developed or adopted by voluntary 
consensus to carry out policy objectives, so long as such standards are 
not inconsistent with applicable law or otherwise impracticable. In 
reviewing program submissions, EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Absent a prior 
existing requirement for the state to use voluntary consensus 
standards, EPA has no authority to disapprove a program submission for 
failure to use such standards, and it would thus be inconsistent with 
applicable law for EPA to use voluntary consensus standards in place of 
a program submission that otherwise satisfies the provisions of the 
Act. Redesignation is an action that affects the status of a 
geographical area but does not impose any new requirements on sources. 
Thus, the requirements of section 12(d) of the National Technology 
Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) do not apply.

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Nitrogen dioxide, Ozone, Volatile organic compounds.

40 CFR Part 81

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

    Dated: June 12, 2007.
Bharat Mathur,
Acting Regional Administrator, Region 5.
[FR Doc. E7-11958 Filed 6-19-07; 8:45 am]

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