[Federal Register Volume 68, Number 131 (Wednesday, July 9, 2003)]
[Proposed Rules]
[Pages 40861-40864]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-17340]



[[Page 40861]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MD146-3100, FRL-7525-9]


Approval and Promulgation of Implementation Plans; Maryland; 
Revised Mobile Source Inventories and Motor Vehicle Emissions Budgets 
for 2005 Developed Using MOBILE6

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve revisions to the Maryland State 
Implementation Plan (SIP). Specifically, EPA is proposing approval of 
revised mobile emission inventories and 2005 motor vehicle emissions 
budgets which have been developed using MOBILE6, an updated model for 
calculating mobile emissions of ozone precursors. These inventories and 
associated motor vehicle emissions budgets are part of the 1-hour ozone 
attainment plans approved for the Metropolitan Baltimore nonattainment 
area (the Baltimore area) and the Cecil County portion of the 
Philadelphia-Wilmington-Trenton nonattainment area (the Philadelphia 
area). The intended effect of this action is to approve SIP revisions 
that will better enable the State of Maryland to continue to plan for 
attainment of the 1-hour national ambient air quality standard (NAAQS) 
for ozone in the Baltimore area and the Cecil County portion of the 
Philadelphia area. This action is being taken under the Clean Air Act.

DATES: Written comments must be received on or before August 8, 2003.

ADDRESSES: Comments may be submitted either by mail or electronically. 
Written comments should be mailed to Robert Kramer, Chief, Energy, 
Radiation and Indoor Environment, Mailcode 3AP23, U.S. Environmental 
Protection Agency, Region III, 1650 Arch Street, Philadelphia, 
Pennsylvania 19103. Electronic comments should be sent either to 
[email protected] or to http://www.regulations.gov, which is an 
alternative method for submitting electronic comments to EPA. To submit 
comments, please follow the detailed instructions described in Part III 
of the Supplementary Information section. Copies of the documents 
relevant to this action are available for public inspection during 
normal business hours at the Air Protection Division, U.S. 
Environmental Protection Agency, Region III, 1650 Arch Street, 
Philadelphia, Pennsylvania 19103; Maryland Department of the 
Environment, 1800 Washington Boulevard, Suite 705, Baltimore, Maryland 
21230. The documents can also be viewed at the Maryland Department of 
the Environment's web site at: http://www.mde.state.md.us/Programs/AirPrograms/air_planning/index.asp.

FOR FURTHER INFORMATION CONTACT: Martin T. Kotsch, Energy, Radiation 
and Indoor Environment Branch, U.S. Environmental Protection Agency, 
1650 Arch Street, Mail Code 3AP23, Philadelphia Pennsylvania 19103-
20209, (215) 814-3335, or by e-mail at [email protected].

SUPPLEMENTARY INFORMATION: 

I. Background

    The MOBILE model is an EPA emissions factor model for estimating 
pollution from on-road motor vehicles in states outside of California. 
The MOBILE model calculates emissions of volatile organic compounds 
(VOCs), nitrogen oxides (NOX) and carbon monoxide (CO) from 
passenger cars, motorcycles, buses, and light-duty and heavy-duty 
trucks. The model accounts for the emission impacts of factors such as 
changes in vehicle emission standards, changes in vehicle populations 
and activity, and variation in local conditions such as temperature, 
humidity, fuel quality, and air quality programs. The MOBILE model is 
used to calculate current and future inventories of motor vehicle 
emissions at the national and local level. These inventories are used 
to make decisions about air pollution policies and programs at the 
local, state and national level. Inventories based on MOBILE are also 
used to meet the federal Clean Air Act's SIP and transportation 
conformity requirements.
    The MOBILE model was first developed in 1978. It has been updated 
many times to reflect changes in the vehicle fleet and fuels, to 
incorporate EPA's growing understanding of vehicle emissions, and to 
cover new emissions regulations and modeling needs. EPA officially 
released the MOBILE6 motor vehicle emissions factor model on January 
29, 2002 (67 FR 4254). Although some minor updates were made in 1996 
with the release of MOBILE5b, MOBILE6 is the first major revision to 
MOBILE since MOBILE5a was released in 1993.
    In November of 1999, EPA issued two memoranda \1\ to articulate its 
policy regarding states that incorporated MOBILE5-based interim Tier 2 
standard \2\ benefits into their attainment demonstration plans and 
those plans' associated motor vehicle emissions budgets (budgets). EPA 
has implemented this policy in all ozone nonattainment areas where a 
state assumed federal Tier 2 benefits in its attainment demonstration 
plans according to EPA's April 2000 MOBILE5 guidance, ``MOBILE5 
Information Sheet 8: Tier 2 Benefits Using MOBILE5.'' All 
states whose attainment demonstrations or maintenance plans include 
interim MOBILE5-based estimates of the Tier 2 standards were required 
to revise and resubmit their budgets within either 1 or 2 years of the 
final release of MOBILE6.
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    \1\ Memoranda, ``Guidance on Motor Vehicle Emissions Budgets in 
1-Hour Ozone Attainment Demonstrations,'' issued November 3, 1999, 
and ``1-Hour Ozone Attainment Demonstrations and Tier2/Sulfur 
Rulemaking,'' issued November 8, 1999. Copies of these memoranda can 
be found on EPA's Web site at http://www.epa.gov/otaq/transp/traqconf.htm.
    \2\ The final rule on Tier 2 Motor Vehicle Emissions Standards 
and Gasoline Sulfur Control Requirements (``Tier 2 standards'') for 
passenger cars, light trucks, and larger passenger vehicles was 
published on February 10, 2000 (65 FR 6698).
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    On October 29, 2001 (66 FR 54596), EPA approved the attainment 
demonstration plan submitted by the State of Maryland for the 
Philadelphia area which includes Cecil County, Maryland. On October 30, 
2001 (66 FR 54687), EPA approved the attainment demonstration plan 
submitted by the State of Maryland for the Baltimore area. Both of 
these attainment plans included, among other things, interim MOBILE5-
based budgets which assumed estimates of the benefits of the Tier 2 
standards.

II. Summary of the SIP Revisions and EPA's Evaluation

A. The Revised Emission Inventories

    On May 28, 2003, the State of Maryland submitted proposed SIP 
revisions, and requested that EPA parallel process its approval of 
those SIP revisions concurrent with the State's process for amending 
its SIP. These proposed SIP revisions revise the 1990 and 2005 motor 
vehicle emissions inventories and the 2005 motor vehicle emissions 
budgets using the MOBILE6 model. The May 28, 2003 submittal 
demonstrates that the new levels of motor vehicle emissions calculated 
using MOBILE6 continue to support the demonstrations of attainment of 
the 1-hour ozone NAAQS for the Baltimore and Philadelphia areas by 
2005.
    Table 1 below summarizes the revised motor vehicle emissions 
inventories by nonattainment area in tons per summer day (tpd). These 
revised inventories were developed using the latest

[[Page 40862]]

planning assumptions, including 2002 vehicle registration data, vehicle 
miles traveled (VMT), speeds, fleet mix, and SIP control measures.

                        Table 1.--Maryland's Revised Motor Vehicle Emissions Inventories
----------------------------------------------------------------------------------------------------------------
                                                                    1990 (tpd)                 2005 (tpd)
                    Nonattainment area                     -----------------------------------------------------
                                                                 VOC           NOX          VOC          NOX
----------------------------------------------------------------------------------------------------------------
Baltimore.................................................        165.14        228.21         55.3        146.9
Cecil County..............................................          8.6          17.3           3.0         11.3
----------------------------------------------------------------------------------------------------------------

    EPA has articulated its policy regarding the use of MOBILE6 in SIP 
development in its ``Policy Guidance on the Use of MOBILE6 for SIP 
Development and Transportation Conformity''\3\ and ``Clarification of 
Policy Guidance for MOBILE6 in Mid-course Review Areas.''\4\
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    \3\ Memorandum, ``Policy Guidance on the Use of MOBILE6 for SIP 
development and Transportation Conformity,'' issued January 18, 
2002. A copy of this memorandum can be found on EPA's Web site at 
http://www.epa.gov/otaq/transp/traqconf.htm.
    \4\ Memorandum, ``Clarification of Policy Guidance for MOBILE6 
SIPs in Mid-course Review Areas,'' issued February 12, 2003. A copy 
of this memorandum can be found on EPA's Web site at http://www.epa.gov/otaq/transp/traqconf.htm.
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    Consistent with this policy guidance, Maryland's May 28, 2003 
submittal includes a relative reduction comparison to show that its 1-
Hour Ozone Attainment Demonstration Plan continues to demonstrate 
attainment using revised MOBILE6 inventories for the Baltimore area and 
the Philadelphia area (Cecil County). The State's methodology for the 
relative reduction comparison consisted of comparing the new MOBILE6 
inventories with the previously approved (64 FR 64028) MOBILE5 
inventories for the Baltimore area and the Cecil County portion of the 
Philadelphia area to determine if attainment will still be predicted by 
the established 2005 attainment date. Specifically, the State 
calculated the relative reductions (expressed as percent reductions) in 
ozone precursors between the MOBILE5-based 1990 base year and 
attainment year inventory. These percent reductions were then compared 
to the percent reductions between the revised MOBILE6-based 1990 base 
year and attainment year inventories. It should again be noted that the 
latest planning assumptions were used in modeling for the State's 
relative reduction comparison.
    Maryland's relative reduction comparison shows that for both the 
Baltimore area and the Cecil County portion of the Philadelphia area, 
the percent reductions in VOC emissions achieved in the revised 
MOBILE6-based inventories is higher than the percent reductions 
calculated with MOBILE5, however the percent reductions of 
NOX emissions achieved in the revised MOBILE6-based 
inventories is lower than the percent reductions calculated with 
MOBILE5, thus a slight NOX shortfall is indicated for both 
areas.
    In support of Maryland's Phase I Ozone SIP for Cecil County and 
Baltimore, approved by EPA on September 19, 2001 (66 FR 48209) and 
September 26, 2001 (66 FR 49108) respectively, it was determined that 
reductions in both VOC and NOX emissions are valuable and 
contribute toward attaining the 1-hour ozone standard. Based upon the 
emission inventories and using EPA guidance titled ``NOX 
Substitution'' United States Environmental Protection Agency, Office of 
Air Quality Planning and Standards, dated December 1993, it was 
determined that for the Baltimore area approximately 1 ton of VOC 
emissions is equivalent to 1.44 tons of NOX emissions, as 
emissions of those pollutants relate to their potential to form ozone. 
In Cecil County, approximately 1 ton of VOC emissions is equivalent to 
1.35 tons of NOX emissions, as emissions of those pollutants 
relate to their potential to form ozone.
    Maryland's May 28, 2003 submittal shows that the shortfalls in the 
percent of NOX emission reductions are offset by the 
excesses in percent of VOC emission reductions. As provided for under 
section 182(c)(2)(C) of the Clean Air Act and EPA's policy on 
substitution of ozone precursor emission reductions, the State 
submittal demonstrates that excesses of VOC reductions are available 
and sufficient to account for the shortfalls in NOX 
reductions calculated using the 1 to 1.44 and 1 to 1.35 ratios for the 
Baltimore area and Cecil County, respectively. Thus, when MOBILE6 is 
used, the required mobile emission reductions needed to attain the 1-
hour ozone NAAQS are still achieved for the Baltimore and Philadelphia 
areas, and Maryland's attainment demonstration SIPs continue to 
demonstrate attainment.
    EPA's policy guidance also required the State to consider whether 
growth and control strategy assumptions for non-motor vehicle sources 
(i.e., point, area, and non-road mobile sources) were still accurate at 
the time the May 28, 2003 submittal was developed. Maryland reviewed 
the growth and control strategy assumptions for non-motor vehicle 
sources, and concluded that these assumptions continue to be valid for 
its 1-hour Ozone Attainment Demonstrations.
    Maryland's May 28, 2003 submittal satisfies the conditions outlined 
in EPA's MOBILE6 Policy guidance, and demonstrates that the new levels 
of motor vehicle emissions calculated using MOBILE6 continue to support 
achievement of the projected attainment of the 1-Hour Ozone NAAQS by 
the attainment date of 2005 for both the Baltimore and Philadelphia 
areas (Cecil County).

B. The Revised Mobile Budgets

    For the Baltimore area and Philadelphia area (Cecil County) 
attainment plans, the mobile budgets are the on-road components of VOC 
and NOX emissions of the 2005 attainment inventories.
    Table 2 below summarizes Maryland's revised budgets contained in 
the May 28, 2003 submittal. These budgets were developed using the 
latest planning assumptions, including 2002 vehicle registration data, 
VMT, speeds, fleet mix, and SIP control measures. Because Maryland's 
May 28, 2003 submittal satisfies the conditions outlined in EPA's 
MOBILE6 Policy guidance, and demonstrates that the new levels of motor 
vehicle emissions calculated using MOBILE6 continue to support 
achievement of the projected attainment of the 1-Hour Ozone NAAQS by 
the attainment date of November 15, 2005 for both the Baltimore and 
Philadelphia areas (Cecil County), EPA is proposing to approve these 
budgets.

[[Page 40863]]



           Table 2.--Maryland Motor Vehicle Emissions Budgets
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                                                         2005 Attainment
                                                              (tpd)
                  Nonattainment Area                   -----------------
                                                          VOC      NOX
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Baltimore.............................................     55.3    146.9
Cecil County..........................................      3.0     11.3
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III. Proposed EPA Action

    EPA's review of this material indicates that Maryland has 
demonstrated that its revised 1-Hour Attainment Demonstration SIPs for 
the Baltimore area and the Philadelphia area (Cecil County) continue to 
demonstrate attainment while incorporating the revised MOBILE6 
inventories. EPA is proposing to approve the Maryland SIP revisions 
which were submitted on May 28, 2003 and revise Maryland's 1990 and 
2005 motor vehicle emission inventories and 2005 motor vehicle 
emissions budgets for the Baltimore area and Cecil County using 
MOBILE6. These revisions are being proposed under a procedure called 
parallel processing, whereby EPA proposes rulemaking action concurrent 
with the State's procedures for amending its SIP. If the proposed 
revisions are substantially changed in areas other than those 
identified in this notice, EPA will evaluate those changes and may 
publish another notice of proposed rulemaking. If no substantial 
changes are made other than those areas cited in this notice, EPA will 
publish a Final Rulemaking Notice on the revisions. The final 
rulemaking action by EPA will occur only after the SIP revisions have 
been adopted by Maryland and submitted formally to EPA for 
incorporation into the SIP. EPA is soliciting public comments on the 
issues discussed in this document. These comments will be considered 
before taking final action. Interested parties may participate in the 
Federal rulemaking procedure by submitting either electronic or written 
comments. To ensure proper receipt by EPA, identify the appropriate 
rulemaking identification number MD146-3100 in the subject line on the 
first page of your comment. Please ensure that your comments are 
submitted within the specified comment period. Comments received after 
the close of the comment period will be marked ``late.'' EPA is not 
required to consider these late comments.
    1. Electronically. If you submit an electronic comment as 
prescribed below, EPA recommends that you include your name, mailing 
address, and an e-mail address or other contact information in the body 
of your comment. Also include this contact information on the outside 
of any disk or CD ROM you submit, and in any cover letter accompanying 
the disk or CD ROM. This ensures that you can be identified as the 
submitter of the comment and allows EPA to contact you in case EPA 
cannot read your comment due to technical difficulties or needs further 
information on the substance of your comment. EPA's policy is that EPA 
will not edit your comment, and any identifying or contact information 
provided in the body of a comment will be included as part of the 
comment that is placed in the official public docket. 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.
    i. E-mail. Comments may be sent by electronic mail (e-mail) to 
[email protected], attention MD146-3100. EPA's e-mail system is not 
an ``anonymous access'' system. If you send an e-mail comment directly 
without going through Regulations.gov, EPA's e-mail system 
automatically captures your e-mail address. E-mail addresses that are 
automatically captured by EPA's e-mail system are included as part of 
the comment that is placed in the official public docket.
    ii. Regulations.gov. Your use of Regulation.gov is an alternative 
method of submitting electronic comments to EPA. Go directly to 
Regulations.gov at http://www.regulations.gov, then select 
``Environmental Protection Agency'' at the top of the page and use the 
``go'' button. The list of current EPA actions available for comment 
will be listed. Please follow the online instructions for submitting 
comments. The system is an ``anonymous access'' system, which means EPA 
will not know your identity, e-mail address, or other contact 
information unless you provide it in the body of your comment.
    iii. Disk or CD ROM. You may submit comments on a disk or CD ROM 
that you mail to the mailing address identified in the ADDRESSES 
section of this document. These electronic submissions will be accepted 
in WordPerfect, Word or ASCII file format. Avoid the use of special 
characters and any form of encryption.
    2. By Mail. Written comments should be addressed to the EPA 
Regional office listed in the ADDRESSES section of this document.
    For public commenters, it is important to note that EPA's policy is 
that public comments, whether submitted electronically or in paper, 
will be made available for public viewing at the EPA Regional Office, 
as EPA receives them and without change, unless the comment contains 
copyrighted material, confidential business information (CBI), or other 
information whose disclosure is restricted by statute. When EPA 
identifies a comment containing copyrighted material, EPA will provide 
a reference to that material in the version of the comment that is 
placed in the official public rulemaking file. The entire printed 
comment, including the copyrighted material, will be available at the 
Regional Office for public inspection.

Submittal of CBI Comments

    Do not submit information that you consider to be CBI 
electronically to EPA. You may claim information that you submit to EPA 
as CBI by marking any part or all of that information as CBI (if you 
submit CBI on disk or CD ROM, mark the outside of the disk or CD ROM as 
CBI and then identify electronically within the disk or CD ROM the 
specific information that is CBI). Information so marked will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2.
    In addition to one complete version of the comment that includes 
any information claimed as CBI, a copy of the comment that does not 
contain the information claimed as CBI must be submitted for inclusion 
in the official public regional rulemaking file. If you submit the copy 
that does not contain CBI on disk or CD ROM, mark the outside of the 
disk or CD ROM clearly that it does not contain CBI. Information not 
marked as CBI will be included in the public file and available for 
public inspection without prior notice. If you have any questions about 
CBI or the procedures for claiming CBI, please consult the person 
identified in the FOR FURTHER INFORMATION CONTACT section.

Considerations When Preparing Comments to EPA

    You may find the following suggestions helpful for preparing your 
comments:
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide any technical information and/or data you used that 
support your views.
    4. If you estimate potential burden or costs, explain how you 
arrived at your estimate.
    5. Provide specific examples to illustrate your concerns.
    6. Offer alternatives.

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    7. Make sure to submit your comments by the comment period deadline 
identified.
    8. To ensure proper receipt by EPA, identify the appropriate 
regional file/rulemaking identification number in the subject line on 
the first page of your response. It would also be helpful if you 
provided the name, date, and Federal Register citation related to your 
comments.

IV. 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 FR 28355, May 22, 2001). This 
proposed 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 tribal implications because 
it will not have a substantial direct effect on one or more Indian 
tribes, on the relationship between the Federal Government and Indian 
tribes, or on the distribution of power and responsibilities between 
the Federal Government and Indian tribes, as specified by Executive 
Order 13175 (65 FR 67249, November 9, 2000). This action also does not 
have Federalism implications because it does not have substantial 
direct effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government, as specified 
in Executive Order 13132 (64 FR 43255, August 10, 1999). This action 
merely proposes to approve a state rule implementing a Federal 
standard, 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 ``Protection 
of Children from Environmental Health Risks and Safety Risks'' (62 FR 
19885, April 23, 1997), because it is not economically significant.
    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. 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.
    This rule proposing to approve Maryland's revised 1990 and 2005 
motor vehicle emission inventories and 2005 motor vehicle emissions 
budgets using MOBILE6 for the Baltimore area and Cecil County 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 in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Nitrogen dioxide, Ozone, Particulate matter, Reporting and 
recordkeeping requirements, Sulfur dioxides, Volatile organic 
compounds.

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

    Dated: June 27, 2003.
Thomas Voltaggio,
Acting Regional Administrator, Region III.
[FR Doc. 03-17340 Filed 7-8-03; 8:45 am]
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