	ENVIRONMENTAL PROTECTION AGENCY

	40 CFR Parts 52 and 81

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

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 [insert date 30
days from date of publication].  

ADDRESSES:  Submit your comments, identified by Docket ID Number
EPA-R03-OAR-2007-0344 by one of the following methods:

A.  www.regulations.gov.  Follow the on-line instructions for submitting
comments.

      B.  E-mail:    HYPERLINK "mailto:Cripps.Christopher@epa.gov" 
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 www.regulations.gov, including any personal
information provided, unless the comment includes information claimed to
be Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute.  Do not submit information that you
consider to be CBI or otherwise protected through www.regulations.gov or
e-mail.  The www.regulations.gov website is an (anonymous access(
system, which means EPA will not know your identity or contact
information unless you provide it in the body of your comment.  If you
send an e-mail comment directly to EPA without going through
www.regulations.gov, your e-mail address will be automatically captured
and included as part of the comment that is placed in the public docket
and made available on the Internet.  If you submit an electronic
comment, EPA recommends that you include your name and other contact
information in the body of your comment and with any disk or CD-ROM you
submit.  If EPA cannot read your comment due to technical difficulties
and cannot contact you for clarification, EPA may not be able to
consider your comment.  Electronic files should avoid the use of special
characters, any form of encryption, and be free of any defects or
viruses.



Docket:  All documents in the electronic docket are listed in the
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 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 “we,” “us,” or “our” is
used, we mean EPA.

TABLE OF CONTENTS

What Are the Actions EPA Is Proposing to Take?

What Is the Background for These Proposed Actions?

 What Are the Criteria for Redesignation to Attainment?

 Why Is EPA Taking These Actions?

 What Would Be the Effect of These Actions?

 What Is EPA’s Analysis of the Commonwealth’s Request?

 Are the Motor Vehicle Emissions Budgets Established and Identified in
the Maintenance Plan for Mercer County Adequate and Approvable? 

Proposed Actions

Statutory and Executive Order Reviews

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 (D.C.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 D. C. 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-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.  

 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 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 

Year	Annual 4th Highest 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 

Year	Annual 4th Highest 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 

Year	Annual 4th Highest 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

Year	Annual 4th Highest 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 the 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.

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, 12465-66 (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 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, 12465-66 (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, 20469-70, 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, 24830-32 (May 7, 1997). 

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
section 

51.905(a)(1)(ii).

Pursuant to 40 CFR 51.905(c), the Area is subject to the obligations set
forth in 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.

  SEQ CHAPTER \h \r 1 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.

  SEQ CHAPTER \h \r 1 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 considered not relevant to an
action changing an area’s designation.  See 61 FR 53174, 53175-6
(October 10, 1996) and 62 FR 24826, 24830-32 (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)

Volatile Organic Compounds (VOC)

Year	Pennsylvania	Ohio	Total

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) 

Year	Pennsylvania	Ohio	Total

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. 

  Stationary Point Sources 

 Federal NOx SIP Call (66 FR 43795, August 21, 2001)

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
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   HYPERLINK "http://www.airnav.com" 
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 found in the Technical Appendices, which are
part of PADEP’s March 27, 2007 state submittal.

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 25430-32. 

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)

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
maintenance plan.  The Commonwealth will also evaluate the periodic
(every three years) emission inventories prepared under EPA’s
Consolidated Emission Reporting Regulation (40 CFR 51, subpart A) to see
if they exceed the attainment year inventory (2004) by more than 10
percent.  The PADEP will also continue to operate the existing ozone
monitoring station in Mercer County pursuant to 40 CFR part 58
throughout the maintenance period and submit quality-assured ozone data
to EPA through the AQS system.  Section 175A(b) of the CAA states that
eight years following redesignation of Mercer County, PADEP will be
required to submit a second maintenance plan that will ensure attainment
through 2028.  PADEP has made the commitment to meet the requirement
section 175A(b).    

(e) The Maintenance Plan’s Contingency Measures – The contingency
plan provisions are designed to promptly correct a violation of the
NAAQS that occurs after redesignation.  Section 175A of the CAA requires
that a maintenance plan include such contingency measures as EPA deems
necessary to ensure that the Commonwealth will promptly correct a
violation of the NAAQS that occurs after redesignation.  The maintenance
plan should identify the events that would “trigger” the adoption
and implementation of a contingency measure(s), the contingency
measure(s) that would be adopted and implemented, and the schedule
indicating the time frame by which the state would adopt and implement
the measure(s).

The ability of Mercer County to stay in compliance with the 8-hour ozone
standard after redesignation depends upon VOC and NOx emissions in the
Youngstown Area remaining at or below 2004 levels.  The Commonwealth’s
maintenance plan projects VOC and NOx emissions to decrease and stay
below 2004 levels through the year 2018.  The Commonwealth’s
maintenance plan outlines the procedures for the adoption and
implementation of contingency measures to further reduce emissions
should a violation occur.  

Contingency measures will be considered if for two consecutive years the
fourth highest 8-hour ozone concentrations at any of the Youngstown Area
monitors are above 84 ppb.  If this trigger point occurs, the
Commonwealth will evaluate, in cooperation with the Ohio Environmental
Protection Agency, whether additional local emission control measures
should be implemented in order to prevent a violation of the air quality
standard.  PADEP will also analyze the conditions leading to the
excessive ozone levels and evaluate which measures might be most
effective in correcting the excessive ozone levels.  PADEP will also
analyze the potential emissions effect of Federal, state (including
states upwind of Pennsylvania), and local measures that have been
adopted but not yet implemented at the time the excessive ozone levels
occurred.  PADEP will then begin the process of implementing any
selected measures.

Contingency measures will also be considered in the event that a
violation of the 8-hour ozone standard occurs at any of the Youngstown
Area monitors.  In the event of a violation of the 8-hour ozone
standard, PADEP will adopt additional emissions reduction measures as
expeditiously as practicable in accordance with the implementation
schedule listed later in this notice and in the Pennsylvania Air
Pollution Control Act in order to return the Youngstown Area to
attainment with the standard.  Contingency measures to be considered for
Mercer County will include, but not be limited to the following:

Regulatory measures:

- Additional controls on consumer products.

- Additional controls on portable fuel containers.

 Non-Regulatory measures:

- Voluntary diesel engine “chip reflash” (installation software to
correct the defeat      device option on certain heavy-duty diesel
engines).			

- Diesel retrofit, including replacement, repowering or alternative fuel
use, for public         or private local on-road or off-road fleets.	

      - Idling reduction technology for Class 2 yard locomotives.

      - Idling reduction technologies or strategies for truck stops,
warehouses and other                 freight- handling facilities.

-  Accelerated turnover of lawn and garden equipment, especially
commercial          equipment, including promotion of electric
equipment.

	      - Additional promotion of alternative fuel (e.g., biodiesel) for
home heating and agricultural use.

The plan lays out a process to have any regulatory contingency measures
in effect within 19 months of the trigger.  The plan also lays out a
process to implement the non-regulatory contingency measures within
12-24 months of the trigger.

VII.  Are the Motor Vehicle Emissions Budgets Established and Identified
in the Mercer County Maintenance Plan Adequate and Approvable?

A.  What are the Motor Vehicle Emissions Budgets?

Under the CAA, States are required to submit, at various times, control
strategy SIPs and maintenance plans in ozone areas.  These control
strategy SIPs (i.e., RFP SIPs and attainment demonstration SIPs) and
maintenance plans identify and establish MVEBs for certain criteria
pollutants and/or their precursors to address pollution from on-road
mobile sources.  In the maintenance plan, the MVEBs are termed
“on-road mobile source emission budgets.”  Pursuant to 40 CFR part
93 and 51.112, MVEBs must be established in an ozone maintenance plan. 
An MVEB is the portion of the total allowable emissions that is
allocated to highway and transit vehicle use and emissions.  An 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 and revise the MVEBs in control
strategy SIPs and maintenance plans.

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 State’s air quality plan that
addresses pollution from cars and trucks.  “Conformity” to the SIP
means that transportation activities will not cause new air quality
violations, worsen existing violations, or delay timely attainment of or
reasonable progress towards the NAAQS.  If a transportation plan does
not “conform,” most new 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 ensuring
conformity of such transportation activities to a SIP.

When reviewing submitted “control strategy” SIPs or maintenance
plans containing MVEBs, EPA must affirmatively find the MVEB contained
therein “adequate” for use in determining transportation conformity.
 After EPA affirmatively finds the submitted MVEB is adequate for
transportation conformity purposes, that MVEB can be used by state and
federal agencies in determining whether proposed transportation projects
“conform” to the SIP as required by section 176(c) of the CAA. 
EPA’s substantive criteria for determining “adequacy” of a MVEB
are set out in 40 CFR 93.118(e)(4)

EPA’s process for determining “adequacy” consists of three basic
steps:  public notification of a SIP submission, a public comment
period, and EPA’s adequacy finding. This process for 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 finalized 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” on July 1,
2004 (69 FR 40004).  EPA consults this guidance and follows this
rulemaking in making its adequacy determinations.

The MVEBs for Mercer County are listed in Table 1 of this document for
2009 and 2018, and are the projected emissions for the on-road mobile
sources plus any portion of the safety margin allocated to the MVEBs
(safety margin allocation for 2009 and 2018 only).  Note that in a
separate rulemaking action (72 FR 19435, April 18, 2007) EPA proposed
approval of Trumbull, Mahoning, and Columbiana Counties, Ohio MVEBs. 
These emission budgets, when approved by EPA, must be used for
transportation conformity determinations.

B.  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.  The attainment level of emissions
is the level of emissions during one of the years in which the area met
the NAAQS.  The following example is for the 2018 safety margin:  Mercer
County first attained the 8-hour ozone NAAQS during the 2004 to 2006
time period.  The Commonwealth used 2004 as the year to determine
attainment levels of emissions for Mercer County.  The total emissions
from point, area, mobile on-road, and mobile non-road sources in 2004
equaled 19.0 tpsd of VOC and 22.4 tpsd of NOx.  The PADEP projected
emissions out to the year 2018 and projected a total of 17.1 tpsd of VOC
and 13.1 tpsd of NOx from all sources in Mercer County.  The safety
margin for 2018 would be the difference between these amounts, or 1.9
tpsd of VOC and 9.3 tpsd of NOx.  The emissions up to the level of the
attainment year including the safety margins are projected to maintain
the area's air quality consistent with the 8-hour ozone NAAQS.  The
safety margin is the extra emissions reduction below the attainment
levels that can be allocated for emissions by various sources as long as
the total emission levels are maintained at or below the attainment
levels.  Table 8 shows the safety margins for the 2009 and 2018 years.

Table 8:  2009 and 2018 Safety Margins for Mercer County

Inventory Year	VOC Emissions (tpsd)	NOx Emissions (tpsd)

2004 Attainment	19.0	22.4

2009 Interim	18.0	19.1

2009 Safety Margin	1.0	3.3

2004 Attainment	19.0	22.4

2018 Final	17.1	13.1

2018 Safety Margin	1.9	9.3



The PADEP allocated 0.3 tpsd VOC and 0.4 tpsd NOx to the 2009 interim
VOC projected on-road mobile source emissions projection and the 2009
interim NOx projected on-road mobile source emissions projection to
arrive at the 2009 MVEBs.  For the 2018 MVEBs the PADEP allocated 0.4
tpsd VOC and 0.4 tpsd NOx from the 2018 safety margins to arrive at the
2018 MVEBs.  Once allocated to the mobile source budgets these portions
of the safety margins are no longer available, and may no longer be
allocated to any other source category.  Table 9 shows the final 2009
and 2018 MVEBs for Mercer County. 

Table 9:  2009 and 2018 Final MVEBs for Mercer County

Inventory Year	VOC Emissions (tpsd)	NOx Emissions (tpsd)

2009 projected on-road mobile source projected emissions	4.2	11.2

2009 Safety Margin Allocated to MVEBs	0.3	0.4

2009 MVEBs	4.5	11.6

2018 projected on-road mobile source projected emissions	2.6	4.9

2018 Safety Margin Allocated to MVEBs	0.4	0.4

2018 MVEBs	3.0	5.3

				 

C.  Why Are the MVEBs Approvable?

The 2009 and 2018 MVEBs for Mercer County are approvable because the
MVEBs for VOCs and NOx continue to maintain the total emissions at or
below the attainment year inventory levels as required by the
transportation conformity regulations.  Note that in a separate
rulemaking action (72 FR 19435, April 18, 2007) EPA proposed approval of
Trumbull, Mahoning, and Columbiana Counties, Ohio MVEBs.

D.  What Is the Adequacy and Approval Process for the MVEBs in the
Mercer County Maintenance Plan?

The MVEBs for the Mercer County maintenance plan are being posted to
EPA’s conformity Website concurrently with this proposal.  The public
comment period will end at the same time as the public comment period
for this proposed rule.  In this case, EPA is concurrently processing
the action on the maintenance plan and the adequacy process for the
MVEBs contained therein.  In this proposed rule, EPA is proposing to
find the MVEBs adequate and also proposing to approve the MVEBs as part
of the maintenance plan.  The MVEBs cannot be used for transportation
conformity until the maintenance plan and associated MVEBs are approved
in a final Federal Register notice, or EPA otherwise finds the budgets
adequate in a separate action following the comment period.

If EPA receives adverse written comments with respect to the proposed
approval of the Mercer County MVEBs, or any other aspect of our proposed
approval of this updated maintenance plan, we will respond to the
comments on the MVEBs in our final action or proceed with the adequacy
process as a separate action.  Our action on the Mercer County MVEBs
will also be announced on EPA’s conformity Website:    HYPERLINK
"http://www.epa.gov/otaq/stateresources/transconf/index.htm" 
http://www.epa.gov/otaq/stateresources/transconf/index.htm 

(once there, click on “Adequacy Review of SIP Submissions”).

VIII.  Proposed Actions

EPA is proposing to determine that Mercer County has attained the 8-hour
ozone NAAQS.  EPA is also proposing to approve the redesignation of
Mercer County from nonattainment to attainment for the 8-hour ozone
NAAQS.  EPA has evaluated Pennsylvania’s redesignation request and
determined that it meets the redesignation criteria set forth in section
107(d)(3)(E) of the CAA.  EPA believes that the redesignation request
and monitoring data demonstrate that Mercer County has attained the
8-hour ozone standard.  The final approval of this redesignation request
would change the designation of Mercer County from nonattainment to
attainment for the 8-hour ozone standard.  EPA is also proposing to
approve the associated maintenance plan for Mercer County, submitted on
March 27, 2007, as a revision to the Pennsylvania SIP.  EPA is proposing
to approve the maintenance plan for Mercer County because it meets the
requirements of section 175A as described previously in this notice. 
EPA is also proposing to approve the 2002 base-year inventory for Mercer
County, and the MVEBs submitted by Pennsylvania for Mercer County in
conjunction with its redesignation request.  EPA is soliciting public
comments on the issues discussed in this document.  These comments will
be considered before taking final action.

IX.  Statutory and Executive Order Reviews   

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
proposed action is not a "significant regulatory action" and therefore
is not subject to review by the Office of Management and Budget.  For
this reason, this action is also not subject to Executive Order 13211,
"Actions Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use"  (66 Fed. Reg. 28355 (May 22, 2001)).  This action
merely proposes to approve state law as meeting Federal requirements and
imposes no additional requirements beyond those imposed by state law. 
Accordingly, the Administrator certifies that this proposed 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.).  
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 (Public Law 104-4).  This proposed
rule also does not have a substantial direct effect on one or more
Indian tribes, on the relationship between the Federal Government and
Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes, as specified by
Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it 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),
because it merely proposes to approve a state rule implementing a
Federal requirement, and does not alter the relationship or the
distribution of power and responsibilities established in the Clean Air
Act. This proposed rule also is not subject to Executive Order 13045 (62
FR 19885, April 23, 1997), because it approves a state rule implementing
a Federal standard.  In reviewing SIP submissions, EPA(s role is to
approve state choices, provided that they meet the criteria of the Clean
Air Act.  In this context, in the absence of a prior existing
requirement for the State to use voluntary consensus standards (VCS),
EPA has no authority to disapprove a SIP submission for failure to use
VCS.  It would thus be inconsistent with applicable law for EPA, when it
reviews a SIP submission, to use VCS in place of a SIP submission that
otherwise satisfies the provisions of the Clean Air Act.  Redesignation
is an action that affects the status of a geographical area and 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.  As required by section 3 of
Executive Order 12988 (61 FR 4729, February 7, 1996), in issuing this
proposed rule, EPA has taken the necessary steps to eliminate drafting
errors and ambiguity, minimize potential litigation, and provide a clear
legal standard for affected conduct.  EPA has complied with Executive
Order 12630 (53 FR 8859, March 15, 1988) by examining the takings
implications of the rule in accordance with the (Attorney General(s
Supplemental Guidelines for the Evaluation of Risk and Avoidance of
Unanticipated Takings( issued under the executive order.  

This rule, proposing to approve the redesignation of Mercer County to
attainment for the 8-hour ozone NAAQS, the associated maintenance plan,
the 2002 base-year inventory, and the MVEBs identified in the
maintenance plan, does not impose an information collection burden under
the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et
seq.).

List of Subjects 

40 CFR Part 52

Environmental protection, Air pollution control, Nitrogen oxides, Ozone,
Reporting and recordkeeping requirements, Volatile organic compounds. 

40 CFR Part 81

Air pollution control, National parks, Wilderness Areas.

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

___________________________           	______/s/____________________

Dated:  July 16, 2007                                    	Donald S.
Welsh,

Regional Administrator,

                                                                 	Region
III.

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