2014-09719. Adequacy Status of the Submitted Maintenance Plan for the District of Columbia Portion of the Metropolitan Washington, DC, (DC-MD-VA) 1997 Fine Particulate National Ambient Air Quality Standard Nonattainment Area for Transportation ...

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of adequacy.

SUMMARY:

In this notice, the Environmental Protection Agency (EPA) is notifying the public that EPA has found that the motor vehicle emissions budgets (MVEBs) in the District of Columbia portion of the Metropolitan Washington, DC, (DC-MD-VA) 1997 Fine Particulate (PM_2.5) National Ambient Air Quality Standard (NAAQS) Nonattainment Area (hereafter, the Washington Area) Maintenance Plan, submitted as a State Implementation Plan (SIP) revision by District of Columbia Department of the Environment (DDOE), are adequate for transportation conformity purposes.

DATES:

This finding is effective on May 14, 2014.

FOR FURTHER INFORMATION CONTACT:

Gregory Becoat, Physical Scientist, Office of Air Program Planning (3AP30), United States Environmental Protection Agency, Region III, 1650 Arch Street, Philadelphia, PA 19103, [phone]; [e-mail].

SUPPLEMENTARY INFORMATION:

Today's notice is simply an announcement of a finding that EPA has already made. EPA Region III sent a letter to DDOE on March 25, 2014, stating that EPA has found that the MVEBs in the Washington Area's Maintenance Plan for budget years 2017 and 2025, submitted on June 3, 2013 by DDOE, are adequate for transportation conformity purposes. As a result of EPA's finding, the District of Columbia must use the 2017 and 2025 Tier 1 MVEBs shown in Table 1 from the Washington Area's Maintenance Plan for future conformity determinations for the 1997 PM_2.5 NAAQS. The Tier 2 MVEBS shown in Table 2 adds a twenty percent (20%) transportation buffer to the mobile emissions inventory projections for PM_2.5 and nitrogen oxides (NO_X) in 2017 and 2025. The Tier 2 MVEBs will become effective if it is determined that technical uncertainties primarily due to model changes and to vehicle fleet turnover, which may affect future motor vehicle emissions inventories, lead to motor vehicle emissions estimates above the Tier 1 MVEBs. The determination will be made through the interagency consultation process and fully documented within the first conformity analysis that uses the Tier 2 MVEBs. Receipt of the submittal was announced on EPA's transportation conformity Web site. No comments were received. The findings letter is available at EPA's conformity Web site: http://www.epa.gov/​otaq/​stateresources/​transconf/​adequacy.htm. The adequate direct particulate matter (PM) and NO_X MVEBs for Tier 1 and Tier 2 are provided in Table 1 and Table 2.

Table 1—Tier 1 On-Road MVEBs Contained in the Washington Area Maintenance Plan for the 1997 PM_2.5 NAAQS

Year	Motor vehicle emissions budget for PM2.5 on-road emissions (tons per year)	Mobile vehicle emissions budget for NOX on-road emissions (tons per year)
2017	1,787	41,709
2025	1,350	27,400

Table 2—Tier 2 On-Road MVEBs Contained in the Washington Area Maintenance Plan for the 1997 PM_2.5 NAAQS

Year	Motor vehicle emissions budget for PM2.5 on-road emissions (tons per year)	Mobile vehicle emissions budget for NOX on-road emissions (tons per year)
2017	2,144	50,051
2025	1,586	32,880

Transportation conformity is required by section 176(c) of the Clean Air Act (CAA). EPA's conformity rule requires that transportation plans, transportation improvement programs, and projects conform to SIPs and establishes the criteria and procedures for determining whether or not they do. Conformity to a SIP means that transportation activities will not produce new air quality violations, worsen existing violations, or delay timely attainment of the national ambient air quality standards.

The criteria by which we determine whether a SIP's MVEBs are adequate for conformity purposes are outlined in 40 CFR 93.118(e)(4). EPA described the process for determining the adequacy of submitted SIP budgets in a July 1, 2004 preamble starting at 69 FR 40038 and used the information in these resources in making this adequacy determination. The District of Columbia did not provide emission budgets for sulfur dioxide (SO₂), volatile organic compounds (VOCs), or ammonia for the Washington Area's Maintenance Plan because it concluded that emissions of these precursors from motor vehicles are not significant contributors to the area's PM_2.5 air quality problem. The transportation conformity rule provision at 40 CFR 93.102(b)(2)(v) indicates that conformity does not apply for these precursors, due to the lack of motor vehicle emissions budgets for these precursors and state's conclusion that motor vehicle emissions of SO₂, VOCs, and ammonia do not contribute significantly to the area's PM_2.5 nonattainment problem. This provision of the transportation conformity rule predates and was not disturbed by the January 4, 2013 decision in the litigation on the PM_2.5 implementation rule.

EPA has preliminarily concluded that the District's decision to not include budgets for SO₂, VOCs, and ammonia is consistent with the requirements of the transportation conformity rule. That decision does not affect EPA's adequacy finding for the submitted direct PM and NO_X MVEBs for the Washington Area's Maintenance Plan.

Please note that an adequacy review is separate from EPA's completeness review, and should not be used to prejudge EPA's ultimate approval action for the SIP. Even if EPA finds the budgets for the Washington Area's Maintenance Plan adequate, the SIP could later be disapproved. The finding and the response to comments are available at EPA's conformity Web site: http://www.epa.gov/​otaq/​stateresources/​transconf/​adequacy.htm.

Authority: 42 U.S.C. 7401-7671q.

Dated: April 11, 2014.

W. C. Early, Acting

Regional Administrator, Region III.