	ENVIRONMENTAL PROTECTION AGENCY

	40 CFR Part 52

	[EPA-R03-OAR-2008-0181; FRL-        ]

Approval and Promulgation of Air Quality Implementation Plans;
Pennsylvania; Section 110(a)(1) 8-Hour Ozone Maintenance Plan and 2002
Base-Year Inventory for the Somerset County Area

AGENCY:  Environmental Protection Agency (EPA).

ACTION:  Proposed rule

SUMMARY:  EPA is proposing to approve a State Implementation Plan (SIP)
revision submitted by the Commonwealth of Pennsylvania.  The
Pennsylvania Department of Environmental Protection (PADEP) submitted a
SIP revision consisting of a maintenance plan that provides for
continued attainment of the 8-hour ozone national ambient air quality
standard (NAAQS) for at least 10 years after the April 30, 2004
designations, as well as a 2002 base-year inventory for the Somerset
County Area.  EPA is proposing approval of the maintenance plan and the
2002 base-year inventory in accordance with the requirements of the
Clean Air Act (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-2008-0181 by one of the following methods:

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

     B.    E-mail:  fernandez.cristina@epa.gov

     C.    Mail:   EPA-R03-OAR-2008-0181, Cristina Fernandez, 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-2008-0181.  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 Pennsylvania Department of Environmental Protection,
Bureau of Air Quality Control, P.O. Box 8468, 400 Market Street,
Harrisburg, Pennsylvania 17105.

FOR FURTHER INFORMATION CONTACT: Gregory Becoat, (215) 814-2036, or by
e-mail at becoat.gregory@epa.gov.

SUPPLEMENTARY INFORMATION:  On December 17, 2007, PADEP formally
submitted for approval, under section 110(a)(1) of the CAA, a SIP
revision for the 8-hour ozone maintenance plan and the 2002 base-year
inventory for the Somerset County Area.  

I.  Background

Section 110(a)(1) of the CAA requires that states submit to EPA plans to
maintain the NAAQS promulgated by EPA.  EPA interprets this provision to
require that areas that were maintenance areas for the 1-hour ozone
NAAQS, but attainment for the 8-hour ozone NAAQS, submit a plan to
demonstrate the continued maintenance of the 8-hour ozone NAAQS.  

On May 20, 2005, EPA issued guidance that applies to areas that are
designated unclassifiable/attainment for the 8-hour ozone standard.  The
purpose of this guidance is to address the maintenance requirements in
section 110(a)(1) of the CAA, and to assist the states in the
development of a SIP.  The components from EPA’s guidance include:

(1) An attainment emissions inventory, which is based on actual
“typical summer day” emissions of volatile organic compounds (VOCs)
and nitrogen oxides (NOx) for a 10-year maintenance period, from a
base-year chosen by the state; (2) a maintenance demonstration, which
demonstrates how the area will remain in compliance with the 8-hour
ozone standard for a period of 10 years following the effective date of
designation unclassifiable/attainment (June 15, 2004); (3) an ambient
air monitoring network, which will be in continuous operation in
accordance with 40 CFR Part 58 to verify maintenance of the 8-hour ozone
standard; (4) a contingency plan, that will ensure that in the event of
a violation of the 8-hour ozone NAAQS, measures will be implemented as
promptly as possible; (5) a verification of continued attainment,
indicating how the state intends on tracking the progress of the
maintenance plan.

II.   Summary of SIP Revision

The Commonwealth of Pennsylvania has requested approval of its 8-hour
ozone maintenance plan and 2002 base-year inventory for the Somerset
County Area.  The PADEP 8-hour ozone maintenance plan addresses the five
components of EPA’s May 20, 2005 guidance, which pertains to the
maintenance requirements in section 110(a)(1) of the CAA.

Attainment Emission Inventory:  An attainment emissions inventory
includes emissions during the time period associated with the monitoring
data showing attainment.  PADEP has provided an emissions inventory for
VOCs and NOx, using 2002 as the base-year from which to project
emissions.  The 2002 inventory is consistent with EPA guidance, is based
on actual “typical summer day” emissions of VOCs and NOx, and
consists of a list of sources and their associated emissions.  PADEP
prepared comprehensive VOCs and NOx emissions inventories for the
Somerset County Area.  In the maintenance plan, PADEP included
information on the man-made sources of ozone precursors, VOCs and NOx
(e.g., “stationary sources,” “stationary area sources,”
“highway vehicles,” and “nonroad sources”).  

Pennsylvania projected emissions for beyond 10 years from the effective
date of the April 30, 2004 designations for the 8-hour ozone standard. 
PADEP has developed an emissions inventory for ozone precursors for the
year 2002, 2009, and 2018.  Tables 1 and 2 show the VOCs and NOx
emissions reduction summary for 2002, 2009, and 2018. 

Table 1. - VOC Emissions Summary:  2002, 2009 and 2018

(tons per summer day)

                                 

Major Source Category	2002	2009	2018

Stationary Point Sources	0.21	0.18	0.24

Stationary Area Sources	5.63	5.09	5.24

Highway Vehicles	6.10	3.11	1.81

Nonroad Sources	3.05	3.04	2.29

TOTAL	14.99	11.42	9.58



Table 2. - NOx Emissions Summary:  2002, 2009 and 2018

(tons per summer day)

Major Source Category	2002	2009	2018

Stationary Point Sources	0.62	0.66	0.74

Stationary Area Sources	0.54	0.57	0.57

Highway Vehicles	15.44	8.15	3.14

Nonroad Sources	5.39	4.22	3.25

TOTAL	21.99	13.60	7.70



EPA believes Pennsylvania has demonstrated that the VOCs and NOx
emissions in the Somerset County Area will improve due to permanent and
enforceable reductions in emissions resulting from implementation of the
SIP, federal measures, and other state-adopted measures.  

Maintenance demonstration:  As Table 1 and 2 indicate, the Somerset
County Attainment Area plan shows maintenance of the 8-hour ozone NAAQS
by demonstrating that future emissions of VOCs and NOx remain at or
below the 2002 base-year emissions levels through the year 2018.  

Based upon the comparison of the projected emissions and the 2002
base-year inventory emissions, along federal and state measures, EPA
concludes that PADEP successfully demonstrates that the 8-hour ozone
standard will be maintained in the Somerset County Area. Further details
of Somerset County Attainment Area’s 8-hour ozone maintenance
demonstration can be found in a Technical Support Document (TSD)
prepared for this rulemaking.

Ambient Air Quality Monitoring:  With regard to the ambient air
monitoring component of the maintenance plan, Pennsylvania commits to
continue operating its current air quality monitoring stations in
accordance with 40 CFR Part 58, to verify the attainment status of the
area, with no reductions in the number of sites from those in the
existing network unless pre-approved by EPA.

Contingency Plan:  Section 110(a)(1) of the CAA requires that the state
develop a contingency plan which will ensure that any violation of a
NAAQS is promptly corrected.  The purpose of the contingency plan is to
adopt measures, outlined in the maintenance plan, in order to assure
continued attainment in the event of a violation of the 8-hour ozone
NAAQS.  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).  

Since the Somerset County Area does not have a monitor, contingency
measures will be considered if for two consecutive years the fourth
highest 8-hour ozone concentrations at the design monitor for the
Cambria County Area are above 84 parts per billion (ppb).  If this
trigger point occurs, PADEP will evaluate whether additional local
emission control measures should be implemented in Somerset County in
order to prevent a violation of the air quality standard.  PADEP will
analyze the conditions leading to the excessive ozone levels and
evaluate what measures might be most effective in correcting the
excessive ozone levels.  PADEP will also analyze the potential emissions
effect of federal, state, 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 the contingency
measures outlined in their maintenance plan.  

Verification of continued attainment:  PADEP will track the attainment
status of the 8-hour ozone NAAQS for Somerset County by reviewing air
quality at the design monitor for the Cambria County Area and emissions
data during the maintenance period.  An annual evaluation of vehicle
miles traveled and emissions reported from stationary sources will be
performed and compared to the assumptions about the factors used in the
maintenance plan. PADEP will also evaluate the periodic (every three
years) emission inventories prepared under EPA’s Consolidated Emission
Reporting Regulation (40 CFR, 51 Subpart A) for any unanticipated
increases.  Based on these evaluations, PADEP will consider whether any
further emission control measures should be implemented.

III.   Proposed Action

EPA is proposing to approve the maintenance plan and the 2002 base-year
inventory for the Somerset County Area, submitted on December 17, 2007,
as revisions to the Pennsylvania SIP.  EPA is proposing to approve the
maintenance plan and 2002 base-year inventory for the Somerset County
Area because it meets the requirements of section 110(a)(1) of the CAA. 
EPA is soliciting public comments on the issues discussed in this
document.  These comments will be considered before taking final action.


IV. Statutory and Executive Order Reviews   

Under the CAA, the Administrator is required to approve a SIP submission
that complies with the provisions of the Act and applicable Federal
regulations.  42 U.S.C. 7410(k); 40 CFR 52.02(a).  Thus, in reviewing
SIP submissions, EPA’s role is to approve state choices, provided that
they meet the criteria of the CAA.  Accordingly, this action merely
proposes to approve state law as meeting Federal requirements and does
not impose additional requirements beyond those imposed by state law. 
For that reason, this proposed action:

is not a "significant regulatory action” subject to review by the
Office of Management and Budget under Executive Order 12866 (58 FR
51735, October 4, 1993);  

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

is certified as not having a significant economic impact on a
substantial number of small entities under the Regulatory Flexibility
Act (5 U.S.C. 601 et seq.);  

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);

does not have Federalism implications as specified in Executive Order
13132 (64 FR 43255, August 10, 1999);

is not an economically significant regulatory action based on health or
safety risks subject to Executive Order 13045 (62 FR 19885, April 23,
1997); 

is not a significant regulatory action subject to Executive Order 13211
(66 FR 28355, May 22, 2001); 

is not subject to requirements of Section 12(d) of the National
Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note)
because application of those requirements would be inconsistent with the
CAA; and 

does not provide EPA with the discretionary authority to address, as
appropriate, disproportionate human health or environmental effects,
using practicable and legally permissible methods, under Executive Order
12898 (59 FR 7629, February 16, 1994).

In addition, this proposed rule to approve the maintenance plan and the
2002 base-year inventory for the Somerset County Area in the
Commonwealth of Pennsylvania does not have tribal implications as
specified by Executive Order 13175 (65 FR 67249, November 9, 2000),
because the SIP is not approved to apply in Indian country located in
the state, and EPA notes that it will not impose substantial direct
costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52  

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



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

___May 1, 2008_____________                                   
_________/s/___________________

Dated:                                                                  
          Donald S. Welsh,

                                                                        
               Regional Administrator,

                                                                        
               Region III.

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