03-17340. 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.

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 [e-mail] 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, [phone], or by e-mail at [e-mail].

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 (NO_X) 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.

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 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

Nonattainment area	1990 (tpd)		2005 (tpd)
	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]

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 NO_X emissions achieved in the revised MOBILE6-based inventories is lower than the percent reductions calculated with MOBILE5, thus a slight NO_X 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 NO_X emissions are valuable and contribute toward attaining the 1-hour ozone standard. Based upon the emission inventories and using EPA guidance titled “NO_X 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 NO_X 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 NO_X 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 NO_X 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 NO_X 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 NO_X 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.

Table 2.—Maryland Motor Vehicle Emissions Budgets

Nonattainment Area	2005 Attainment (tpd)
	VOC	NOX
Baltimore	55.3	146.9
Cecil County	3.0	11.3

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 [e-mail], 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.

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.

Footnotes

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).

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.