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[Federal Register: July 27, 2007 (Volume 72, Number 144)]
[Proposed Rules]               
[Page 41246-41258]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27jy07-14]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R03-OAR-2007-0344; FRL-8447-1]

 
Approval and Promulgation of Air Quality Implementation Plans; 
Pennsylvania; Redesignation of the Mercer County Portion of the 
Youngstown-Warren-Sharon, OH-PA 8-Hour Ozone Nonattainment Area to 
Attainment and Approval of the Associated Maintenance Plan and 2002 
Base-Year Inventory

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: EPA is proposing to approve a redesignation request and State 
Implementation Plan (SIP) revision submitted by the Commonwealth of 
Pennsylvania. The Pennsylvania Department of Environmental Protection 
(PADEP) is requesting that the Mercer County portion of the Youngstown-
Warren-Sharon, OH-PA ozone nonattainment area (``Youngstown Area'' or 
``Area'') be redesignated as attainment for the 8-hour ozone national 
ambient air quality standard (NAAQS). The Area is comprised of Mercer 
County, Pennsylvania and Trumbull, Mahoning, and Columbiana Counties, 
Ohio. In this rulemaking action EPA is proposing to approve the ozone 
redesignation request, maintenance plan, and 2002 base year inventory 
for Mercer County. In a separate rulemaking action (72 FR 19435, April 
18, 2007) EPA proposed to approve the ozone redesignation request for 
Trumbull, Mahoning, and Columbiana Counties. In conjunction with its 
redesignation request, the Commonwealth submitted a SIP revision 
consisting of a maintenance plan for Mercer County that provides for 
continued attainment of the 8-hour ozone NAAQS for at least 10 years 
after redesignation. EPA is proposing to make a determination that 
Mercer County has attained the 8-hour ozone NAAQS, based upon three 
years of complete, quality-assured ambient air quality monitoring data 
for 2004-2006. EPA's proposed approval of the 8-hour ozone 
redesignation request is based on its determination that the Area has 
met the criteria for redesignation to attainment specified in the Clean 
Air Act (CAA). In addition, the Commonwealth of Pennsylvania has also 
submitted a 2002 base-year inventory for Mercer County, and EPA is 
proposing to approve that inventory for Mercer County as a SIP 
revision. EPA is also providing information on the status of its 
adequacy determination for the motor vehicle emission budgets (MVEBs) 
that are identified in the maintenance plan for Mercer County for 
purposes of transportation conformity, and is also proposing to approve 
those MVEBs. Note that separate conformity budgets are being 
established by Ohio for Trumbull, Mahoning, and Columbiana Counties. 
EPA is proposing approval of the redesignation request and of the 
maintenance plan and 2002 base-year inventory SIP revisions in 
accordance with the requirements of the CAA.

DATES: Written comments must be received on or before August 27, 2007.

ADDRESSES: Submit your comments, identified by Docket ID Number EPA-
R03-OAR-2007-0344 by one of the following methods:
    A. http://www.regulations.gov. Follow the on-line instructions for 

submitting comments.
    B. E-mail: Cripps.Christopher@epa.gov.
    C. Mail: EPA-R03-OAR-2007-0344, Christopher Cripps, Acting Chief, 
Air Quality Planning Branch, Mailcode 3AP21, U.S. Environmental 
Protection Agency, Region III, 1650 Arch Street, Philadelphia, 
Pennsylvania 19103.
    D. Hand Delivery: At the previously-listed EPA Region III address. 
Such deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-R03-OAR-
2007-0344. 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.
    Docket: All documents in the electronic docket are listed in the 
http://www.regulations.gov index. Although listed in the index, some 

information is not publicly available, i.e., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, is not placed on the Internet and will be 
publicly available only in hard copy form. Publicly available docket 
materials are available either electronically in http://www.regulations.gov
 or in hard copy during normal business hours at the 

Air Protection Division, U.S. Environmental Protection Agency, Region 
III, 1650 Arch Street, Philadelphia, Pennsylvania 19103. Copies of the 
State submittal are available at the Pennsylvania Department of 
Environmental Protection Bureau of Air Quality Control, P.O. Box 8468, 
400 Market Street, Harrisburg, Pennsylvania 17105.

FOR FURTHER INFORMATION CONTACT: Amy Caprio, (215) 814-2156, or by e-
mail at caprio.amy@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document whenever

[[Page 41247]]

``we,'' ``us,'' or ``our'' is used, we mean EPA.

Table Of Contents

I. What Are the Actions EPA Is Proposing To Take?
II. What Is the Background for These Proposed Actions?
III. What Are the Criteria for Redesignation to Attainment?
IV. Why Is EPA Taking These Actions?
V. What Would Be the Effect of These Actions?
VI. What Is EPA's Analysis of the Commonwealth's Request?
VII. Are the Motor Vehicle Emissions Budgets Established and 
Identified in the Maintenance Plan for Mercer County Adequate and 
Approvable?
VIII. Proposed Actions
IX. Statutory and Executive Order Reviews

I. What Are the Actions EPA Is Proposing To Take?

    On March 27, 2007, the PADEP formally submitted a request to 
redesignate Mercer County from nonattainment to attainment of the 8-
hour NAAQS for ozone. Concurrently, Pennsylvania submitted a 
maintenance plan for Mercer County as a SIP revision to ensure 
continued attainment throughout the Youngstown Area over the next 11 
years. PADEP also submitted a 2002 base-year inventory for Mercer 
County as a SIP revision. The Youngstown Area is comprised of Mercer 
County, Pennsylvania and Trumbull, Mahoning, and Columbiana Counties, 
Ohio. It is currently designated a basic 8-hour ozone nonattainment 
area. EPA is proposing to determine that Mercer County has attained the 
8-hour ozone NAAQS and that it has met the requirements for 
redesignation pursuant to section 107(d)(3)(E) of the CAA. EPA is, 
therefore, proposing to approve the redesignation request to change the 
designation of Mercer County from nonattainment to attainment for the 
8-hour ozone NAAQS. EPA is also proposing to approve the Mercer County 
maintenance plan as a SIP revision for Mercer County (such approval 
being one of the CAA criteria for redesignation to attainment status). 
The maintenance plan is designed to ensure continued attainment in 
Mercer County for the next 11 years. EPA is also proposing to approve 
the 2002 base-year inventory for Mercer County as a SIP revision. 
Additionally, EPA is announcing its action on the adequacy process for 
the MVEBs identified in the Mercer County maintenance plan, and 
proposing to approve the MVEBs identified for volatile organic 
compounds (VOCs) and nitrogen oxides (NOX) for Mercer County 
for transportation conformity purposes. Note that in a separate 
rulemaking action (72 FR 19435, April 18, 2007) EPA is proposing to 
approve Trumbull, Mahoning, and Columbiana Counties, Ohio MVEBs.

II. What Is the Background for These Proposed Actions?

A. General

    Ground-level ozone is not emitted directly by sources. Rather, 
emissions of NOX and VOC react in the presence of sunlight 
to form ground-level ozone. The air pollutants NOX and VOC 
are referred to as precursors of ozone. The CAA establishes a process 
for air quality management through the attainment and maintenance of 
the 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. EPA designated, as nonattainment, 
any area violating the 8-hour ozone NAAQS based on the air quality data 
for the three years of 2001-2003. These were the most recent three 
years of data at the time EPA designated 8-hour areas. The Youngstown 
Area was designated a basic 8-hour ozone nonattainment area in a 
Federal Register notice signed on April 15, 2004 and published on April 
30, 2004 (69 FR 23857), based on its exceedance of the 8-hour health-
based standard for ozone during the years 2001-2003.
    On April 30, 2004, EPA issued a final rule (69 FR 23951, 23996) to 
revoke the 1-hour ozone NAAQS in the Youngstown Area (as well as most 
other areas of the country), effective June 15, 2005. See, 40 CFR 
50.9(b); 69 FR at 23996 (April 30, 2004); 70 FR 44470 (August 3, 2005).
    However, 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 FR 23951, April 30, 2004). South 
Coast Air Quality Management Dist. v. EPA, 472 F.3d 882 (DC Cir. 2006) 
(hereafter ``South Coast''). On June 8, 2007, in South Coast Air 
Quality Management Dist. v. EPA, Docket No. 04-1201, in response to 
several petitions for rehearing, the DC Circuit clarified that the 
Phase 1 Rule was vacated only with regard to those parts of the rule 
that had been successfully challenged. Therefore, the Phase 1 Rule 
provisions related to classifications for areas currently classified 
under subpart 2 of Title I, part D of the Act as 8-hour nonattainment 
areas, the 8-hour attainment dates and the timing for emissions 
reductions needed for attainment of the 8-hour ozone NAAQS remain 
effective. The June 8 decision left intact the Court's rejection of 
EPA's reasons for implementing the 8-hour standard in certain 
nonattainment areas under Subpart 1 in lieu of subpart 2. By limiting 
the vacatur, the Court let stand EPA's revocation of the 1-hour 
standard and those anti-backsliding provisions of the Phase 1 Rule that 
had not been successfully challenged. The June 8 decision reaffirmed 
the December 22, 2006 decision that EPA had 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 transportation conformity requirements for certain 
types of federal actions. The June 8 decision clarified that the 
Court's reference to conformity requirements was limited to requiring 
the continued use of 1-hour motor vehicle emissions budgets until 8-
hour budgets were available for 8-hour conformity determinations. 
Elsewhere in this document, mainly in section VI.B. ``Mercer County Has 
Met All Applicable Requirements Under Section 110 and Part D of the CAA 
and Has a Fully Approved SIP Under Section 110(k) of the CAA,'' EPA 
discusses its rationale why the decision in South Coast is not an 
impediment to redesignating Mercer County to attainment of the 8-hour 
ozone NAAQS.
    The CAA, title I, Part D, contains two sets of provisions--subpart 
1 and subpart 2--that address planning and control requirements for 
nonattainment areas. Subpart 1 (which EPA refers to as ``basic'' 
nonattainment) contains general, less prescriptive requirements for 
nonattainment areas for any pollutant--including ozone--governed by a 
NAAQS. Subpart 2 (which EPA refers to as ``classified'' nonattainment) 
provides more specific requirements for ozone nonattainment areas. In 
2004, the Youngstown Area was classified a basic 8-hour ozone 
nonattainment area based on air quality monitoring data from 2001-2003. 
Therefore, the Youngstown Area is subject to the requirements of 
subpart 1 of Part D.
    Under 40 CFR part 50, the 8-hour ozone standard is attained when 
the 3-

[[Page 41248]]

year average of the annual fourth-highest daily maximum 8-hour average 
ambient air quality ozone concentrations is less than or equal to 0.08 
ppm (i.e., 0.084 ppm when rounding is considered). See 69 FR 23857 
(April 30, 2004) for further information. Ambient air quality 
monitoring data for the 3-year period must meet data completeness 
requirements. The data completeness requirements are met when the 
average percent of days with valid ambient monitoring data is greater 
than 90 percent, and no single year has less than 75 percent data 
completeness as determined in Appendix I of 40 CFR part 50. The ozone 
monitoring data indicates that the Youngstown Area has a design value 
of 0.083 ppm for the 3-year period of 2004-2006, using complete, 
quality-assured data. Therefore, the ambient ozone data for the 
Youngstown Area indicates no violations of the 8-hour ozone standard.

 B. The Youngstown Area

    The Youngstown Area consists of Mercer County, Pennsylvania and 
Mahoning, Trumbull, and Columbiana Counties, Ohio. Prior to its 
designation as an 8-hour ozone nonattainment area, the Youngstown Area 
was a marginal 1-hour ozone nonattainment area, and therefore, was 
subject to requirements for marginal nonattainment areas pursuant to 
section 182(a) of the CAA. See 56 FR 56694 (November 6, 1991). EPA 
determined that the Youngstown Area has attained the 1-hour ozone NAAQS 
by the November 15, 1993 attainment date (60 FR 3349, January 17, 
1995). The Ohio counties were subsequently redesignated as attainment 
(Mahoning and Trumbull Counties on January 31, 1996 (61 FR 3319) and 
Columbiana County on February 8, 1995 (60 FR 7453)).
    On March 27, 2007, the PADEP requested that Mercer County be 
redesignated to attainment for the 8-hour ozone standard. The 
redesignation request included three years of complete, quality-assured 
data for the period of 2004-2006, indicating that the 8-hour NAAQS for 
ozone had been achieved in the Youngstown Area. The data satisfies the 
CAA requirements that the 3-year average of the annual fourth-highest 
daily maximum 8-hour average ozone concentration (commonly referred to 
as the area's design value), must be less than or equal to 0.08 ppm 
(i.e., 0.084 ppm when rounding is considered). Under the CAA, a 
nonattainment area may be redesignated if sufficient complete, quality-
assured data is available to determine that the area attained the 
standard and the area meets the other CAA redesignation requirements 
set forth in section 107(d)(3)(E).

III. What Are the Criteria for Redesignation to Attainment?

    The CAA provides the requirements for redesignating a nonattainment 
area to attainment. Specifically, section 107(d)(3)(E) of the CAA, 
allows for redesignation, providing that:
    (1) EPA determines that the area has attained the applicable NAAQS;
    (2) EPA has fully approved the applicable implementation plan for 
the area under section 110(k);
    (3) EPA 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) EPA 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 redesignations 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 Bill Laxton, 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 (TSDs) 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;
     Memorandum from D. Kent Berry, Acting Director, Air 
Quality Management Division, to Air Division Directors, Regions 1-10, 
``Use of Actual Emissions in Maintenance Demonstrations for Ozone and 
CO Nonattainment Areas,'' 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.

IV. Why Is EPA Taking These Actions?

    On March 27, 2007, the PADEP requested redesignation of Mercer 
County to attainment for the 8-hour ozone standard. On March 27, 2007, 
PADEP submitted a maintenance plan for Mercer County as a SIP revision, 
to ensure continued attainment of the 8-hour ozone NAAQS over the next 
11 years, until 2018. PADEP also submitted a 2002 base-year inventory 
concurrently with its maintenance plan as a SIP revision. EPA has 
determined that Mercer County has attained the 8-hour ozone standard 
and has met the requirements for redesignation set forth in section 
107(d)(3)(E).

V. What Would Be the Effect of These Actions?

    Approval of the redesignation request would change the official 
designation of Mercer County from nonattainment to attainment for the 
8-hour ozone NAAQS found at 40 CFR part 81. It would also incorporate 
into the Pennsylvania SIP a 2002 base-year inventory and a maintenance 
plan ensuring continued attainment of the 8-hour ozone NAAQS in Mercer 
County for the next 11 years, until 2018. The maintenance plan

[[Page 41249]]

includes contingency measures to remedy any future violations of the 8-
hour NAAQS (should they occur), and identifies the NOX and 
VOC MVEBs (Mercer County only) for transportation conformity purposes 
for the years 2009 and 2018. These MVEBs are displayed in the following 
table:

   Table 1.--Mercer County Motor Vehicle Emissions Budgets in Tons per
                            Summer Day (tpsd)
------------------------------------------------------------------------
                         Year                             VOC      NOX
------------------------------------------------------------------------
2009..................................................      4.2     11.2
2018..................................................      2.6      4.9
------------------------------------------------------------------------

VI. What Is EPA's Analysis of the Commonwealth's Request?

    EPA is proposing to determine that Mercer County has attained the 
8-hour ozone standard, and that all other redesignation criteria have 
been met. The following is a description of how the PADEP's March 27, 
2007 submittal satisfies the requirements of section 107(d)(3)(E) of 
the CAA.

A. Mercer County Has Attained the 8-Hour NAAQS

    EPA is proposing to determine that Mercer County 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 Appendix I of Part 50, 
based on three complete, consecutive calendar years of quality-assured 
air quality monitoring data. To attain this standard, the design value, 
which is the 3-year average of the fourth-highest daily maximum 8-hour 
average ozone concentrations measured at each monitor, within the area, 
over each year must not exceed the ozone standard of 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 Air Quality System (AQS). The monitors 
generally should have remained at the same location for the duration of 
the monitoring period required for demonstrating attainment.
    In the Youngstown Area, there are four ozone monitors, one located 
in Mahoning County, Ohio, two located in Trumbull County, Ohio and one 
in Mercer County, Pennsylvania that measure air quality with respect to 
ozone. As part of its redesignation request, Pennsylvania referenced 
ozone monitoring data for the years 2004-2006 for the Youngstown Area. 
This data has been quality assured and is recorded in the AQS. The 
PADEP uses the AQS as the permanent database to maintain its data and 
quality assures the data transfers and content for accuracy. The 
fourth-high 8-hour daily maximum concentrations, along with the three-
year average are summarized in Tables 2-5.

  Table 2.--Youngstown Area Fourth Highest 8-hour Average Values Mercer
             County, Pennsylvania Monitor/AQS ID 42-085-0100
------------------------------------------------------------------------
                                                              Annual 4th
                                                               highest
                            Year                               reading
                                                                (ppm)
------------------------------------------------------------------------
2004.......................................................        0.076
2005.......................................................        0.087
2006.......................................................        0.079
------------------------------------------------------------------------
        The average for the 3-year period 2004-2006 is 0.079 ppm
------------------------------------------------------------------------

 Table 3.--Youngstown Area Fourth Highest 8-hour Average Values Mahoning
                 County, Ohio Monitor/AQS ID 39-099-0013
------------------------------------------------------------------------
                                                              Annual 4th
                                                               highest
                            Year                               reading
                                                                (ppm)
------------------------------------------------------------------------
2004.......................................................        0.074
2005.......................................................        0.083
2006.......................................................        0.076
------------------------------------------------------------------------
        The average for the 3-year period 2004-2006 is 0.077 ppm
------------------------------------------------------------------------

 Table 4.--Youngstown Area Fourth Highest 8-hour Average Values Trumbull
                 County, Ohio Monitor/AQS ID 39-155-0009
------------------------------------------------------------------------
                                                              Annual 4th
                                                               highest
                            Year                               reading
                                                                (ppm)
------------------------------------------------------------------------
2004.......................................................        0.078
2005.......................................................        0.083
2006.......................................................        0.074
------------------------------------------------------------------------
        The average for the 3-year period 2004-2006 is 0.078 ppm
------------------------------------------------------------------------

 Table 5.--Youngstown Area Fourth Highest 8-hour Average Values Trumbull
                 County, Ohio Monitor/AQS ID 39-155-0011
------------------------------------------------------------------------
                                                              Annual 4th
                                                               highest
                            Year                               reading
                                                                (ppm)
------------------------------------------------------------------------
2004.......................................................        0.080
2005.......................................................        0.087
2006.......................................................        0.082
------------------------------------------------------------------------
        The average for the 3-year period 2004-2006 is 0.083 ppm
------------------------------------------------------------------------

    The air quality data for 2004-2006 show that the Youngstown Area 
has attained the standard with a design value of 0.083 ppm. The data 
collected at the Youngstown Area monitors satisfy the CAA requirement 
that 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. The 
PADEP's request for redesignation for Mercer County indicates that the 
data is complete and was quality assured in accordance with 40 CFR part 
58. In addition, as discussed below with respect to the maintenance 
plan, PADEP has committed to continue monitoring in accordance with 40 
CFR part 58. In summary, EPA has determined that the data submitted by 
Pennsylvania and data taken from AQS indicate that the Youngstown Area 
has attained the 8-hour ozone NAAQS.

B. Mercer County Has Met All Applicable Requirements Under Section 110 
and Part D of the CAA and Has a Fully Approved SIP Under Section 110(k) 
of the CAA

    EPA has determined that Mercer County has met all SIP requirements 
applicable for purposes of this redesignation under section 110 of the 
CAA (General SIP Requirements) and that it meets all applicable SIP 
requirements under Part D of Title I of the CAA, in accordance with 
section 107(d)(3)(E)(v). In addition, EPA has determined that the SIP 
is fully approved with respect to all requirements applicable for 
purposes of redesignation in accordance with section 107(d)(3)(E)(ii). 
In making these proposed determinations, EPA ascertained which 
requirements are applicable to Mercer County and determined that the 
applicable portions of the SIP meeting these requirements are fully 
approved under section 110(k) of the CAA. We note that SIPs must be 
fully approved only with respect to applicable requirements.

[[Page 41250]]

    The September 4, 1992 Calcagni memorandum (``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) with respect to the timing of applicable requirements. 
Under this interpretation, to qualify for redesignation, States 
requesting redesignation to attainment must meet only the relevant CAA 
requirements that came due prior to the submittal of a complete 
redesignation request. See also, Michael Shapiro memorandum, September 
17, 1993, and 60 FR 12459, 12465-12466 (March 7, 1995) (redesignation 
of Detroit-Ann Arbor). Applicable requirements of the CAA that come due 
subsequent to the area's submittal of a complete redesignation request 
remain applicable until a redesignation is approved, but are not 
required as a prerequisite to redesignation. Section 175A(c) of the 
CAA. Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004). See also, 68 FR 
at 25424, 25427 (May 12, 2003) (redesignation of St. Louis).
    This section sets forth EPA's views on the potential effect of the 
Court's rulings on this proposed redesignation action. For the reasons 
set forth below, EPA does not believe that the Court's rulings alter 
any requirements relevant to this redesignation action so as to 
preclude redesignation, and do not prevent EPA from proposing or 
ultimately finalizing this redesignation. EPA believes that the Court's 
December 22, 2006 and June 8, 2007 decisions impose no impediment to 
moving forward with redesignation of this area to attainment, because 
even in light of the Court's decisions, redesignation is appropriate 
under the relevant redesignation provisions of the Act and longstanding 
policies regarding redesignation requests.
1. Section 110 General SIP Requirements
    Section 110(a)(2) of Title I of the CAA delineates the general 
requirements for a SIP, which includes enforceable emissions 
limitations and other control measures, means, or techniques, 
provisions for the establishment and operation of appropriate devices 
necessary to collect data on ambient air quality, and programs to 
enforce the limitations. The general SIP elements and requirements set 
forth in section 110(a)(2) include, but are not limited to the 
following:
     Submittal of a SIP that has been adopted by the State 
after reasonable public notice and hearing;
     Provisions for establishment and operation of appropriate 
procedures needed to monitor ambient air quality;
     Implementation of a source permit program; provisions for 
the implementation of Part C requirements (Prevention of Significant 
Deterioration (PSD));
     Provisions for the implementation of Part D requirements 
for New Source Review (NSR) permit programs;
     Provisions for air pollution modeling; and
     Provisions for public and local agency participation in 
planning and emission control rule development.
    Section 110(a)(2)(D) requires that SIPs contain certain 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 in accordance with the NOX SIP Call, October 
27, 1998 (63 FR 57356), amendments to the NOX SIP Call, May 
14, 1999 (64 FR 26298) and March 2, 2000 (65 FR 11222), and the Clean 
Air Interstate Rule (CAIR), May 12, 2005 (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 in that 
State. 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. The 
transport SIP submittal requirements, where applicable, continue to 
apply to a state regardless of the designation of any one particular 
area in the State. Thus, we do not believe that these requirements are 
applicable requirements for purposes of redesignation.
    In addition, EPA believes that the other section 110 elements not 
connected with nonattainment plan submissions and not linked with an 
area's attainment status are not applicable requirements for purposes 
of redesignation. The Area will still be subject to these requirements 
after it is redesignated. The section 110 and Part D requirements which 
are linked with a particular area's designation and classification are 
the relevant measures to evaluate in reviewing a redesignation request. 
This policy is consistent with EPA's existing policy on applicability 
of conformity (i.e., for redesignations) and oxygenated fuels 
requirement. See Reading, Pennsylvania, proposed and final rulemakings 
(61 FR 53174, 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 redesignation (65 
FR at 37890, June 19, 2000), and in the Pittsburgh redesignation (66 FR 
at 53099, October 19, 2001). Similarly, with respect to the 
NOX SIP Call rules, EPA noted in its Phase 1 Final Rule to 
Implement the 8-hour Ozone NAAQS, that the NOX SIP Call 
rules are not ``an'' 'applicable requirement' for purposes of section 
110(1) because the NOX rules apply regardless of an area's 
attainment or nonattainment status for the 8-hour (or the 1-hour) 
NAAQS.'' 69 FR 23951, 23983 (April 30, 2004).
    EPA believes that section 110 elements not linked to the area's 
nonattainment status are not applicable for purposes of redesignation. 
As we explain later in this notice, no Part D requirements applicable 
for purposes of redesignation under the 8-hour standard became due for 
Mercer County prior to submission of the redesignation request.
2. Part D Nonattainment Requirements Under the 8-Hour Standard
    Pursuant to an April 30, 2004, final rule (69 FR 23951), the 
Youngstown Area was designated a basic nonattainment area under subpart 
1 for the 8-hour ozone standard. Sections 172-176 of the CAA, found in 
subpart 1 of Part D, set 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.
    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 of 
the Area cannot now go forward. This belief is based upon (1) EPA's 
longstanding policy of evaluating redesignation requests in accordance 
with the requirements due at the time the request is submitted; and (2) 
consideration of the inequity of applying retroactively any 
requirements that might in the future be applied.
    First, at the time the redesignation request was submitted, Mercer 
County was classified under subpart 1 and was obligated to meet only 
subpart 1 requirements. Under EPA's longstanding interpretation of 
section

[[Page 41251]]

107(d)(3)(E) of the Clean Air Act, 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. See 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, 12465-12466 (March 7, 1995) (Redesignation of 
Detroit-Ann Arbor); Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004), 
which upheld this interpretation. See 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.
    With respect to 8-hour subpart 2 requirements, if Mercer County 
initially had been classified under subpart 2, the first two Part D 
subpart 2 requirements applicable to Mercer County under section 182(a) 
of the CAA would be: a base-year inventory requirement pursuant to 
section 182(a)(1) of the CAA, and, the emissions statement requirement 
pursuant to section 182(a)(3)(B).
    As stated previously, these requirements are not yet due for 
purposes of redesignation of Mercer County, but nevertheless, 
Pennsylvania already has in its approved SIP, an emissions statement 
rule for the 1-hour standard that covers all portions of the designated 
8-hour nonattainment area and, that satisfies the emissions statement 
requirement for the 8-hour standard. See, 25 Pa. Code 135.21(a)(1), 
codified at 40 CFR 52.2020; 60 FR 2881, January 12, 1995. With respect 
to the base-year inventory requirement, in this notice of proposed 
rulemaking, EPA is proposing to approve the 2002 base-year inventory 
for Mercer County, which was submitted on March 27, 2007, concurrently 
with its maintenance plan, into the Pennsylvania SIP. EPA is proposing 
to approve the 2002 base-year inventory as fulfilling the requirements, 
if necessary, of both section 182(a)(1) and section 172(c)(3) of the 
CAA. A detailed evaluation of Pennsylvania's 2002 base-year inventory 
for Mercer County can be found in a Technical Support Document (TSD) 
prepared by EPA for this rulemaking. EPA has determined that the 
emission inventory and emissions statement requirements for Mercer 
County have been satisfied.
    In addition to the fact that Part D requirements applicable for 
purposes of redesignation did not become due prior to submission of the 
redesignation request, EPA believes that the general conformity and NSR 
requirements do not require approval prior to redesignation.
    With respect to section 176, Conformity Requirements, section 
176(c) of the CAA requires states to establish criteria and procedures 
to ensure that Federally supported or funded projects conform to the 
air quality planning goals in the applicable SIP. The requirement to 
determine conformity applies to transportation plans, programs, and 
projects developed, funded or approved under Title 23 U.S.C. 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 
that the CAA required the EPA to promulgate. EPA believes it is 
reasonable to interpret the conformity SIP requirements as not applying 
for purposes of evaluating the redesignation request under section 
107(d) since State conformity rules are still required after 
redesignation and Federal conformity rules apply where State rules have 
not been approved. See Wall v. EPA, 265 F. 3d 426, 438-440 (6th Cir. 
2001), upholding this interpretation. See also 60 FR 62748 (December 7, 
1995).
    In the case of Mercer County, EPA has also determined that before 
being redesignated, Mercer County need not comply with the requirement 
that a NSR program be approved prior to redesignation. EPA has 
determined that 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 standard without 
Part D NSR in effect. The rationale for this position is described in a 
memorandum from Mary Nichols, Assistant Administrator for Air and 
Radiation, dated October 14, 1994, entitled, ``Part D NSR Requirements 
or Areas Requesting Redesignation to Attainment.'' Normally, State's 
Prevention of Significant Deterioration (PSD) program will become 
effective in the area immediately upon redesignation to attainment. See 
the more detailed explanations in the following redesignation 
rulemakings: Detroit, MI (60 FR 12467-12468 (March 7, 1995); Cleveland-
Akron-Lorrain, OH (61 FR 20458, 20469-20470, May 7, 1996); Louisville, 
KY (66 FR 53665, 53669, October 23, 2001); Grand Rapids, MI (61 FR 
31831, 31836-31837, June 21, 1996). In the case of Mercer County the 
Chapter 127 Part D NSR regulations in the Pennsylvania SIP (codified at 
40 CFR 52.2020(c)(1)) explicitly apply the requirements for NSR in 
section 184 of the CAA to ozone attainment areas within the OTR. The 
OTR NSR requirements are more stringent than that required for a 
marginal or basic ozone nonattainment area. On October 19, 2001 (66 FR 
53094), EPA fully approved Pennsylvania's NSR SIP revision consisting 
of Pennsylvania's Chapter 127 Part D NSR regulations that cover Mercer 
County.
    EPA has also interpreted the section 184 OTR requirements, 
including the NSR program, as not being applicable for purposes of 
redesignation. The rationale for this is based on two considerations. 
First, the requirement to submit SIP revisions for the section 184 
requirements continues to apply to areas in the OTR after redesignation 
to attainment. Therefore, the State remains obligated to have NSR, as 
well as RACT, and Vehicle Inspection and Maintenance (I/M) programs 
even after redesignation. Second, the section 184 control measures are 
region-wide requirements and do not apply to Mercer County by virtue of 
the Area's designation and classification. See 61 FR 53174, 53175-53176 
(October 10, 1996) and 62 FR 24826, 24830-24832 (May 7, 1997).

[[Page 41252]]

3. Part D Nonattainment Area Requirements Under the 1-Hour Standard
    In its June 8, 2007 decision the Court limited its vacatur so as to 
uphold those provisions of the anti-backsliding requirements that were 
not successfully challenged. Therefore the Area must meet the federal 
anti-backsliding requirements, see 40 CFR 51.900, et seq.; 70 FR 30592, 
30604 (May 26, 2005) which apply by virtue of the area's classification 
for the 1-hour ozone NAAQS. As set forth in more detail below, the area 
must also address four additional anti-backsliding provisions 
identified by the Court in its decisions.
    The anti-backsliding provisions at 40 CFR 51.905(a)(1) prescribe 1-
hour ozone NAAQS requirements that continue to apply after revocation 
of the 1-hour ozone NAAQS to former 1-hour ozone nonattainment areas. 
Section 51.905(a)(1)(i) provides that:

    The area remains subject to the obligation to adopt and 
implement the applicable requirements as defined in section 
51.900(f), except as provided in paragraph (a)(1)(iii) of paragraph 
(b) of this section. * * *

    Section 51.900(f), as amended by 70 FR 30592, 30604 (May 26, 2005), 
states that:

    Applicable requirements means for an area the following 
requirements to the extent such requirements applied to the area for 
the area's classification under section 181(a)(1) of the CAA for the 
1-hour NAAQS at the time of designation for the 8-hour NAAQS.
(1) Reasonably available control technology (RACT).
(2) Inspection and maintenance programs (I/M).
(3) Major source applicability cut-offs for purposes of RACT.
(4) Rate of Progress (ROP) reductions.
(5) Stage II vapor recovery.
(6) Clean fuels fleet program under section 183(c)(4) of the CAA.
(7) Clean fuels for boilers under section 182(e)(3) of the CAA.
(8) Transportation Control Measures (TCMs) during heavy traffic 
hours as provided section 182(e)(4) of the CAA.
(9) Enhanced (ambient) monitoring under section 182(c)(1) of the 
CAA.
(10) Transportation control measures (TCMs) under section 182(c)(5) 
of the CAA.
(11) Vehicle miles traveled (VMT) provisions of section 182(d)(1) of 
the CAA.
(12) NOX requirements under section 182(f) of the CAA.
(13) Attainment demonstration or alternative as provided under Sec.  
51.905(a)(1)(ii).

    Pursuant to 40 CFR 51.905(c), the Area is subject to the 
obligations set forth in Sec. Sec.  51.905(a) and 51.900(f).
    Prior to its designation as an 8-hour ozone nonattainment area, the 
Youngstown Area was designated a marginal nonattainment area for the 1-
hour standard. With respect to the 1-hour standard, the applicable 
requirements under the anti-backsliding provisions at 40 CFR 
51.905(a)(1) for the Youngstown Area are limited to RACT and I/M 
programs specified in section 182(a) of the CAA and are discussed in 
the following paragraphs:
    Section 182(a)(2)(A) required SIP revisions to correct or amend 
RACT for sources in marginal areas, such as the Youngstown Area, that 
were subject to control technique guidelines (CTGs) issued before 
November 15, 1990 pursuant to CAA section 108. On December 22, 1994, 
EPA fully approved into the Pennsylvania SIP all corrections required 
under section 182(a)(2)(A) of the CAA (59 FR 65971, December 22, 1994) 
(this covers the Mercer County, PA portion of the Youngstown Area). EPA 
believes that this requirement applies only to marginal and higher 
classified areas under the 1-hour NAAQS pursuant to the 1990 amendments 
to the CAA; therefore, this is a one-time requirement. After an area 
has fulfilled the section 182(a)(2)(A) requirement for the 1-hour 
NAAQS, there is no requirement under the 8-hour NAAQS.
    Section 182(a)(2)(B) relates to the savings clause for vehicle 
inspection and maintenance (I/M). It requires marginal areas to adopt 
vehicle I/M programs. This provision was not applicable to the 
Youngstown Area because this Area did not have and was not required to 
have an I/M program before November 15, 1990.
    In addition the Court held that EPA should have retained four 
additional measures in its anti-backsliding provisions: (1) 
Nonattainment area NSR; (2) Section 185 penalty fees; (3) contingency 
measures under section 172(c)(9) or 182(c)(9) of the Act; and (4) 1-
hour motor vehicle emission budgets that were yet not replaced by 8-
hour emissions budgets. These requirements are addressed below:
    With respect to NSR, EPA has determined that areas being 
redesignated need not have an approved nonattainment New Source Review 
program, for the same reasons discussed previously with respect to the 
applicable Part D requirement for the 8-hour standard.
    The section 185 penalty fee requirement applies only in severe and 
extreme nonattainment areas, and therefore was never applicable in the 
Youngstown 1-hour marginal nonattainment area.
    With respect to the requirement for submission of contingency 
measures for the 1-hour standard, section 182(a) does not require 
contingency measures for marginal areas.
    The conformity portion of the Court's ruling does not impact the 
redesignation request for Mercer County except to the extent that the 
Court in its June 8 decision clarified that for those areas with 1-hour 
MVEBs, anti-backsliding requires that those 1-hour budgets must be used 
for 8-hour conformity determinations until replaced by 8-hour budgets. 
There are no applicable 1-hour MVEBs for Mercer County. (As discussed 
elsewhere in this document, EPA is only proposing to approve 8-hour 
MVEBs for the Mercer County portion of the Youngstown Area.) To meet 
this requirement, conformity determinations in such areas must comply 
with the applicable requirements of EPA's conformity regulations at 40 
CFR part 93. The court clarified that 1-hour conformity determinations 
are not required for anti-backsliding purposes.
    Thus EPA has concluded that Mercer County has met all requirements 
applicable for redesignation under the 1-hour standard.
4. Transport Region Requirements
    All areas in the Ozone Transport Region (OTR), both attainment and 
nonattainment, are subject to additional control requirements under 
section 184 for the purpose of reducing interstate transport of 
emissions that may contribute to downwind ozone nonattainment. The 
section 184 requirements include RACT, NSR, enhanced vehicle inspection 
and maintenance, and Stage II vapor recovery or a comparable measure.
    In the case of Mercer County, which is located in the OTR, 
nonattainment NSR will continue to be applicable after redesignation. 
On October 19, 2001, EPA approved the 1-hour NSR SIP revision for the 
Area. See 66 FR 53094 (October 19, 2001).
    EPA has also interpreted the section 184 OTR requirements, 
including NSR, as not being applicable for purposes of redesignation. 
Reading, PA Redesignation, 61 FR 53174, (October 10, 1996), 62 FR 24826 
(May 7, 1997). The rationale for this is based on two considerations. 
First, the requirement to submit SIP revisions for the section 184 
requirements continues to apply to areas in the OTR after redesignation 
to attainment. Therefore, the State remains obligated to have NSR, as 
well as RACT, and I/M even after redesignation. Second, the section 184 
control measures are region-wide requirements and do not apply to the 
area by virtue of the area's nonattainment designation and 
classification, and thus are properly

[[Page 41253]]

considered not relevant to an action changing an area's designation. 
See 61 FR 53174, 53175-53176 (October 10, 1996) and 62 FR 24826, 24830-
24832 (May 7, 1997).
5. Mercer County Has a Fully Approved SIP for Purposes of Redesignation
    EPA has fully approved the Pennsylvania SIP for the purposes of 
this redesignation. EPA may rely on prior SIP approvals in approving a 
redesignation request. Calcagni Memo, p.3; Southwestern Pennsylvania 
Growth Alliance v. Browner, 144 F. 3d 984, 989-90 (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 at 
25425 (May 12, 2003) and citations therein.

C. The Air Quality Improvement in Mercer County 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

    EPA believes that the Commonwealth has demonstrated that the 
observed air quality improvement in Mercer County is due to permanent 
and enforceable reductions in emissions resulting from implementation 
of the SIP, Federal measures, and other State-adopted measures. 
Emissions reductions attributable to these rules are shown in Table 6.

              Table 6.--Total VOC and NOX Emissions for 2002 and 2004 in Tons per Summer Day (TPSD)
----------------------------------------------------------------------------------------------------------------
                              Year                                 Pennsylvania        Ohio            Total
----------------------------------------------------------------------------------------------------------------
                                        Volatile Organic Compounds (VOC)
----------------------------------------------------------------------------------------------------------------
2002............................................................            20.8            70.5            91.3
2004............................................................            19.0            64.6            83.6
Difference (02-04)..............................................            -1.8            -5.9            -7.7
----------------------------------------------------------------------------------------------------------------
                                              Nitrogen Oxides (NOX)
----------------------------------------------------------------------------------------------------------------
2002............................................................            25.5            95.5           121.0
2004............................................................            22.4            82.5           104.9
Difference (02-04)..............................................            -3.1           -13.0           -16.1
----------------------------------------------------------------------------------------------------------------

    Between 2002 and 2004, VOC emissions throughout the Area decreased 
by 7.7 tpsd from 91.3 tpsd to 83.6 tpsd; NOX emissions 
throughout the Area decreased by 16.1 tpsd from 121.0 tpsd to 104.9 
tpsd. These reductions, and anticipated future reductions, are due to 
the following permanent and enforceable measures.
1. Stationary Point Sources
    Federal NOX SIP Call (66 FR 43795, August 21, 2001).
2. Stationary Area Sources
    Solvent Cleaning (68 FR 2206, January 16, 2003).
    Portable Fuel Containers (69 FR 70893, December 8, 2004).
3. Highway Vehicle Sources
    Federal Motor Vehicle Control Programs (FMVCP).

--Tier 1 (56 FR 25724, June 5, 1991).
--Tier 2 (65 FR 6698, February 10, 2000).

    Heavy-duty Engine and Vehicle Standards (62 FR 54694, October 21, 
1997, and 65 FR 59896, October 6, 2000).
    National Low Emission Vehicle (NLEV) Program (PA) (64 FR 72564, 
December 28, 1999).
    Vehicle Emission Inspection/Maintenance Program (70 FR 58313, 
October 6, 2005).
4. Non-Road Sources
    Non-road Diesel (69 FR 38958, June 29, 2004).
    EPA believes that permanent and enforceable emissions reductions 
are the cause of the long-term improvement in ozone levels and are the 
cause of Mercer County achieving attainment of the 8-hour ozone 
standard.

D. Mercer County Has a Fully Approvable Maintenance Plan Pursuant to 
Section 175A of the CAA

    In conjunction with its request to redesignate Mercer County to 
attainment status, Pennsylvania submitted a SIP revision to provide for 
maintenance of the 8-hour ozone NAAQS in the Area for at least 11 years 
after redesignation. The Commonwealth is requesting that EPA approve 
this SIP revision as meeting the requirement of CAA 175A. Once 
approved, the maintenance plan for the 8-hour ozone NAAQS will ensure 
that the SIP for Mercer County meets the requirements of the CAA 
regarding maintenance of the applicable 8-hour ozone standard.
What Is Required in a Maintenance Plan?
    Section 175 of the CAA sets forth the 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 10 years after approval of a 
redesignation of an area to attainment. Eight years after the 
redesignation, the Commonwealth must submit a revised maintenance plan 
demonstrating that attainment will continue to be maintained for the 10 
years following the initial 10-year period. To address the possibility 
of future NAAQS violations, the maintenance plan must contain such 
contingency measures, with a schedule for implementation, as EPA deems 
necessary to assure prompt correction of any future 8-hour ozone 
violations. Section 175A of the CAA sets forth the elements of a 
maintenance plan for areas seeking redesignation from nonattainment to 
attainment. The Calcagni memorandum dated September 4, 1992, provides 
additional guidance on the content of a maintenance plan. An ozone 
maintenance plan should address the following provisions:
    (a) an attainment emissions inventory;
    (b) a maintenance demonstration;
    (c) a monitoring network;
    (d) verification of continued attainment; and
    (e) a contingency plan.
Analysis of the Mercer County Maintenance Plan
    (a) Attainment inventory--An attainment inventory includes the

[[Page 41254]]

emissions during the time period associated with the monitoring data 
showing attainment. PADEP determined that the appropriate attainment 
inventory year is 2004. That year establishes a reasonable year within 
the three-year block of 2004-2006 as a baseline and accounts for 
reductions attributable to implementation of the CAA requirements to 
date. The 2004 inventory is consistent with EPA guidance and is based 
on actual ``typical summer day'' emissions of VOC and NOX 
during 2004 and consists of a list of sources and their associated 
emissions.
    The 2002 and 2004 point source data was compiled from actual 
sources. Pennsylvania requires owners and operators of larger 
facilities to submit annual production figures and emission 
calculations each year. Throughput data are multiplied by emission 
factors from Factor Information Retrieval (FIRE) Data Systems and EPA's 
publication series AP-42, and are based on Source Classification Codes 
(SCC). The 2002 area source data was compiled using county-level 
activity data, from census numbers, from county numbers, etc. The 2004 
area source data was projected from the 2002 inventory using temporal 
allocations provided by the Mid-Atlantic Regional Air Management 
Association (MARAMA).
    The on-road mobile source inventories for 2002 and 2004 were 
compiled using MOBILE6.2 and Pennsylvania Department of Transportation 
(PENNDOT) estimates for VMT. The PADEP has provided detailed data 
summaries to document the calculations of mobile on-road VOC and 
NOX emissions for 2002, as well as for the projection years 
of 2004, 2009, and 2018 (shown in Table 8 below). The 2002 and 2004 
emissions for the majority of non-road emission source categories were 
estimated using the EPA NONROAD 2005 model. The NONROAD model 
calculates emissions for diesel, gasoline, liquefied petroleum 
gasoline, and compressed natural gas-fueled non-road equipment types 
and includes growth factors. The NONROAD model does not estimate 
emissions from locomotives or aircraft. For 2002 and 2004 locomotive 
emissions, the PADEP projected emissions from a 1999 survey using 
national fuel consumption information and EPA emission and conversion 
factors. There are no significant commercial aircraft operations 
(aircraft that can seat over 60 passengers) in Mercer County. Mercer 
County airports do not support enough flights or the type of aircraft 
to create measurable emissions from these sources. Emissions from 
airport ground support equipment are considered to be zero. For 2002 
and 2004 aircraft emissions, PADEP estimated emissions using small 
airport operations statistics from http://www.airnav.com, and emission 

factors and operational characteristics in the EPA-approved model, 
Emissions and Dispersion Modeling System (EDMS).
    More detailed information on the compilation of the 2002, 2004, 
2009, and 2018 inventories can be found in the Technical Appendices, 
which are part of PADEP's March 27, 2007 state submittal.
    (b) Maintenance Demonstration--On March 27, 2007, the PADEP 
submitted a maintenance plan as required by section 175A of the CAA. 
The Mercer County maintenance plan shows maintenance of the 8-hour 
ozone NAAQS by demonstrating that current and future emissions of VOC 
and NOX remain at or below the attainment year 2004 
emissions levels throughout Mercer County through the year 2018. A 
maintenance demonstration need not be based on modeling. See, Wall v. 
EPA, supra; Sierra Club v. EPA, supra. See also, 66 FR at 53099-53100; 
68 FR at 25430-25432.
    Table 7 specifies the VOC and NOX emissions for the 
Youngstown Area for 2004, 2009, and 2018. The PADEP chose 2009 as an 
interim year in the maintenance demonstration period to demonstrate 
that the VOC and NOX emissions are not projected to increase 
above the 2004 attainment level during the time of the maintenance 
period.

                Table 7.--VOC and NOX Emissions for The Youngstown Area (TPSD); 2004, 2009, 2018
----------------------------------------------------------------------------------------------------------------
                                            2004                       2009                       2018
                                --------------------------------------------------------------------------------
                                    PA       OH     Total      PA       OH     Total      PA       OH     Total
----------------------------------------------------------------------------------------------------------------
Point.
    VOC........................      1.7      6.0      7.8      2.7      6.4      9.1      3.7      7.8     11.4
    NOX........................      2.9     20.3     23.2      4.3      8.3     12.6      5.5     12.7     18.2
Area.
    VOC........................      7.6     24.1     31.7      7.4     22.9     30.2      7.8     23.0     30.9
    NOX........................      0.8      2.5      3.3      0.9      2.8      3.7      0.9      3.0      3.9
Mobile.
    VOC........................      5.9     26.2     32.1      4.5     19.6     24.1      3.0     10.4     13.4
    NOX........................     15.8     43.5     59.3     11.6     33.7     45.3      5.3     13.3     18.5
Nonroad.
    VOC........................      3.8      8.3     12.1      3.4      6.5      9.9      2.6      5.2      7.8
    NOX........................      2.8     16.3     19.1      2.3     12.5     14.8      1.4      8.2      9.6
Total.
    VOC........................     19.1     64.6     83.6     18.0     55.4     73.4     17.1     46.3     63.4
    NOX........................     22.4     82.5    104.9     19.1     57.4     76.4     13.1     37.2     50.2
----------------------------------------------------------------------------------------------------------------

    Additionally, the following programs are either effective or due to 
become effective and will further contribute to the maintenance 
demonstration of the 8-hour ozone NAAQS:
     The Clean Air Interstate Rule (CAIR) (71 FR 25328, April 
28, 2006).
     The Federal NOX SIP Call (66 FR 43795, August 
21, 2001).
     Area VOC regulations concerning portable fuel containers 
(69 FR 70893, December 8, 2004), consumer products (69 FR 70895, 
December 8, 2004), and architectural and industrial maintenance 
coatings (AIM) (69 FR 68080, November 23, 2004).
     Federal Motor Vehicle Control Programs (light-duty ) (Tier 
1, Tier 2; 56 FR 25724, June 5, 1991; 65 FR 6698, February 10, 2000).
     Vehicle emission/inspection/maintenance program (70 FR 
58313, October 6, 2005).
     Heavy duty diesel on-road (2004/2007) and low sulfur on-
road (2006); 66 FR 5002 (January 18, 2001).

[[Page 41255]]

     Non-road emission standards (2008) and off-road diesel 
fuel (2007/2010); 69 FR 38958 (June 29, 2004).
     NLEV/PA Clean Vehicle Program (54 FR 72564, December 28, 
1999)--Pennsylvania will implement this program in car model year 2008 
and beyond.
     Pennsylvania Heavy-Duty Diesel Emissions Control Program 
(May 10, 2002).
    Based on the comparison of the projected emissions and the 
attainment year emissions along with the additional measures, EPA 
concludes that PADEP has successfully demonstrated that the 8-hour 
ozone standard should be maintained in Mercer County.
    (c) Monitoring Network--There are four ozone monitors located 
throughout the Youngstown Area, one located in Mahoning County, Ohio, 
two located in Trumbull County, Ohio and one in Mercer County, 
Pennsylvania that measure air quality with respect to ozone, in 
accordance with 40 CFR part 58.
    (d) Verification of Continued Attainment--In addition to 
maintaining the key elements of its regulatory program, the 
Commonwealth will track the attainment status of the ozone NAAQS in the 
Youngstown Area by reviewing air quality and emissions data during the 
maintenance period. The Commonwealth will perform an annual evaluation 
of Vehicle Miles Traveled (VMT) data and emissions reported from 
stationary sources, and compare them to the assumptions about these 
factors used in the ma